Whenever we visit relatives in Indonesia, they would always get a box of 24 of Roti Boy for us as we love them so much. In the city where they live, Roti Boy is only available at the airport, so it is always convenient to get them as they come and get us when we land :)
I was informed they are also known as Mexican coffee buns, but back in 2011 when I first making them, I googled and only found so much recipes made by Indonesians, so I don't know the authentic Mexican coffee buns taste like, thus I would say this is Indonesian style of Mexican Coffee Buns :)
Step 1: Ingredients and Method
100 ml water
20 g bread flour
250 g bread flour
50 g regular flour all purpose
90 ml water
25 g margarine
60 g sugar
a pinch of salt (about 1/4 tsp)
1 tsp instant yeast
Salted butter, cubed into 15-20 portions
Into a pot, mix water roux ingredients, stir to combine and try to make it as smooth as you can. Heat on low heat while keep stirring until thickened. Once you see that it's starting to boil, turn it off and beat fast with wire whisk. Let cool to room temperature
Once cooled, add in sugar, yeast, yolks, and water, stir to combine well with the water roux. Lastly add in salt, and stir again.
Add in flour a little at a time and knead. During the kneading, add in margarine and knead until elastic and smooth (about 10-15 minutes). Let rest for 1.5 to 2 hours long, it will be doubled in size. Punch down dough and knead again a little and divide into 18 portions (about 45-50 g each, depending on the weight, you can make between 15-20 portions), let rest for 10 mins.
Once rested, flatten each portion and place 1 butter cube in center and pinch dough to seal, creating round bun shaped. Place buns on lightly greased pan and let rest for 30-40 minutes until doubling in size again, covered.
Meanwhile, make the coffee topping!
50 g each unsalted butter and margarine
100 g icing sugar
100 g egg white
120 g cake flour
20 g full cream powdered milk
1 tbsp coffee mocha paste
1 tsp coffee mocha syrup (I used the one on the picture, but other brand is fine as well! I heard Torani has one too, but the one on my picture is Indonesian brand)
Beat all until combined well then spoon into piping bag/ziplock bag and snip the corner
Preheat oven to 200 C. Pipe topping on buns and bake for 12 minutes.