They're possibly the simplest and best cookies you ever might have the fortune of eating. I swear.
Step 1: Go get stuff
1/2 lb of soft unsalted butter
1/2 cup of packed brown sugar
2 egg yolks
1 tsp vanilla
2 cups of flour
Jelly (grape, strawberry, mint and apricot are crowd favorites)
Step 3: Egg yolks
Crack an egg into a small bowl and gently grab around the egg yolk with your hand lifting it slightly above the bowl. All of the excess egg will drip away and you will be left with just the yolk in your hand.
Place the yolk in the large mixing bowl with the butter/sugar/vanilla mixture.
Repeat the process with the second egg.
Once the yolks are added mash them into the mixture with your wooden cooking spoon.
Step 4: Mix the flour
Mix until the cookie dough is a smooth light brown.
Step 5: Make small balls
When all of the balls are placed, stick your thumb into the center and flatten the ball. This will create both a flatter cookie and a little crater in which you will pour the filling.
Step 6: Add the filling
Don't fill it too much because when you cook it the filling tends to bubble and spread out.
Step 7: Bake
Let them cool for 5 to 10 minutes before removing them from the tray.