Cake challenges are my favorite so when a customer ordered a sculpted Trans Am Cake I had to suggest that we include working LED headlights. I typically only make tiered cakes but this cake was for a car collector who owns the 64th Annual Indy 500 pace car so I had to take it up a notch. :) To see more of my cakes please visit my gallery page on my website Clever Wren Cakes.
For this Instructable you will need the following items:
- 12x18 inch cake (at least two inches high), cooled and chilled
- printed Trans Am pattern x 2 - cars should be 17.5 inches long
- vanilla buttercream - recipe follows
- white chocolate ganache - recipe follows
- cake leveler
- bread knife
- paring knife with very sharp end
- dowel (any size)
- off set spatual
- fondant and food coloring (24-30 ounces white, 10 ounces gray, 8 ounces black, 3 ounces red, 1 ounce orange) These measurements are approximate and chances are you will not need this much. Better too much than too little!
- clear vanilla extract or almond extract
- non-stick pastry mat - not necessary but makes the job easier when rolling fondant
- cake board
- food coloring - red, orange and black
- small food safe paint brush
- bowl or plastic paint palette
- 4 individual battery operated LED lights - white
- 2 lbs powdered sugar
- 1/2 cup water
- 1 cup vegetable shortening (you can substitute butter for a softer buttercream)
- 1 teaspoon vanilla extract
- 1/2 cup butter, softened
In the bowl of a stand mixer add shortening, butter and vanilla. Mix until smooth. Add powdered sugar and water alternately ending with powdered sugar. Mix until completely smooth.
White Chocolate Ganache
- 24 ounces white chocolate
- 8 ounces heavy cream
Place white chocolate in a large mixing bowl. Heat cream in microwave in a heat safe vessel until lightly boiling. Pour over white chocolate and let stand 5 minutes. Mix with spatula until cream is mostly incorporated. Let stand about 30 minutes and then mix with hand mixer until no lumps are visible and mixture thickens a bit.
Step 1: Stack and Carve Cake
The easiest way (in my opinion) to carve a vehicle cake to the correct size and shape is with a printed pattern.
Here are the steps:
- Place cooled and chilled cake on a 13x19 inch cake board.
- Level the cake using a cake leveler (a bread knife if you don't have one) at its lowest point which should be 2ish inches. Do not throw away the cake top. Set aside, it will be used later.
- Determine how wide you would like the car/cake and cut the long end off.
- Spread a thick layer of buttercream only on the car side.
- Stack the side piece on top of the car side and center it in the middle.
- Move the cake gently to angle it on the cake board - not necessary, but I thought it would look better angled!
- Spread buttercream over the top piece and layer with a piece of extra cake top (left over from leveling).
- Next add in pieces to fill the corners and gaps until the stacked cake is tall enough for some to be cut off with the pattern on the side. (see pictures for better understanding!)
- Carve the cake by cutting along the patterns placed on both sides of the cake.
This cake is a bit wider (scale wise) than it actually should be because I had to be able to serve enough guests!
Step 2: Ganache the Cake
After the cake is carved you can 'dirty ice' the cake with ganache. Dirty ice just means covering the cake with a thin layer of ganache (or icing) to catch all the crumbs.
- Using an off set spatula spread a thin layer of ganache over the entire cake.
- Place in fridge to set the ganache for 5-10 minutes.
- Remove cake from fridge and spread a thick layer of ganache smoothing as best as possible.
- Place in fridge again to set the ganache. It should feel very hard once it is set.
Step 3: Cover Cake in Fondant
If you have never worked with fondant before don't be afraid. It's not hard to work with if you have patience!
- Remove cake from fridge.
- On a non-stick pastry mat roll out a large piece of white fondant. About 3 inches larger on all sides than you car.
- Gently lift the fondant as to not tear it and place it over the car.
- Smooth the fondant with your hands and gently work it into place: around and on the bottom edge of the car.
- Trim off excess fondant with a knife. Some people also like using a pizza cutter to trim fondant. Either way, be careful not to cut into your cake.
Step 4: The Details
Details make all the difference. The first photo is the one that was sent to me by my customer of the car she wanted the cake modeled after. I did my best to translate the details in a simplified way.
The Trans Am Phoenix - a definite necessity on this car!
- Using a painters palette (or small bowls) mix 1/4 teaspoon of clear vanilla extract with a small amount of black food coloring in one well to make an opaque black color
- Mix 1/4 teaspoon extract in another well (or bowl) to make a grayish color
- Mix 1/4 teaspoon extract in another well (or bowl) with red to make an opaque red color.
- Mix each color well.
- Cut a piece of white fondant with the bottom being the shape of the phoenix and the top matching up with the hood of the car.
- Attach with clear extract (this is fondant 'glue').
- Using a small (food safe) paint brush apply the 'paint' (food coloring) to the hood of the car making the Phoenix. I printed a Phoenix and used it as a guide to make it look as close to the actual thing as possible, although, I did not completely black out the hood like in the photo.
- Clean brush between colors.
- Using the end of a wooden dowel (or chop stick) make an indent for the side vents.
- Attach with clear extract
- Fill indent with a small piece of black fondant.
Windows and Roof - I didn't have a guide but you could print one to make it more accurate.
- Cut a rectangle roof piece of black fondant.
- Attach with clear extract.
- Cut angled rectangle window pieces from gray fondant.
- Attach with clear extract.
- Outline windows in thin strips of black fondant. Attach with extract.
Back Lights and Bumper
- Roll a snake of black fondant the length of the car.
- Press it to flatten slightly. This will need to be about 1/3 inch tall depending on the size of your car.
- Add notches with toothpick and attach with extract where the lights should be located on the car.
- Roll a very thin snake of red fondant the length of the car.
- Attach it directly underneath the black fondant.
- Roll a snake of gray fondant and place it where the bumper should be, attach with extract.
Tires and Wheel Wells
- Using your fingers press into the fondant (and cake) where the wheel wells should be. Make this deep enough that a tire can be inserted here.
- Repeat three more times for each tire location.
- Roll out a piece of black fondant about 1/2-3/4 inch thick.
- Cut out a circle for the tires to a size appropriate for your car.
- Roll out white fondant about 1/8 inch.
- Cut out a circle about 1 inch smaller than the tire for the rim.
- Attach white circle centering it on the black tire with clear extract.
- Make five very small balls of gray fondant and attach them as shown in the photo of tires.
- Make on slightly larger ball of gray fondant and attach it in the middle of the rim.
- Using the end of a toothpick or small dowel to make indents all around the edge of the rim.
- Repeat three times for a total of four tires.
- Attach where you created wheel well indents with extract.
Decal Words and Logo - I wanted to add the word 'pontiac' to the windshield and the 'turbo trans am' words to the side door.
- Roll a very thin piece of fondant (as thin as possible without tearing) and let sit out to harden and dry a bit before trying to cut.
- Using a very sharp knife cut out the lettering. Unfortunately, there is no good way to explain this other than to just cut them out trying to make them all the same size.
- Repeat with logo - stylize if necessary
- Roll a medium sized oval of white fondant.
- Cut in half and round the edges slightly
- Break one toothpick in half
- Stick one half in each of the mirrors and stick in the car where side mirrors should be located.
- Using a toothpick make indents to outline doors and hood.
- Roll a thin piece of orange fondant.
- Cut four small rectangles and attach on both sides of the car near the back where reflectors should be.
Optional - roll out a very long thin piece of black fondant. Cut to about 1/4 inch thick and place around the entire bottom portion of the car. This will make the car look 'lifted' and not like it is sitting directly on the cake board.
Optional - Roll out a very large piece of gray fondant. Cover the cake board. This was necessary for me since I was making a white car on a white board, but if you are making a red car it wouldn't be so necessary.
Step 5: Headlights
This was the first time I worked with lights in a cake. It is very easy when using balloon LED lights. I purchased balloon lights, cut off the balloon part and removed the LEDs. I'm sure you can purchase them out of a balloon but not in my little town! These lights lasted a very long time. I turned them on a day before the customer was having her party and she sent me a message a few days after the party telling me they were still lit.
I turned all the lights on before putting them in the car. It was a good thing because a few ended up being green! I also wanted to test them. Some will not come on at all and you will have to mess with the connections to get them to turn on. Don't do this last minute if you have an order to get out!!
- Turn headlights on by removing the plastic separator.
- Using a dowel make indents for where the lights will be. It's okay if you push through the fondant into the cake.
- Wrap each LED with plastic wrap being careful not to get the plastic wrap on the bulb.
- Press the LEDs into the indents.
- Cover each LED with a thin piece of white fondant.
Lower the lights and look at your creation!