If you don't have the Martha Stewart's Baking Handbook this recipe comes straight from its pages. I always choose good over simple but this happens to be quite easy and extremely delicious. The only alteration I make is to use 2 different cocoa powders.
Sift dry ingredients straight into your mixing bowl.
2 1/2 C. All-Purpose Flour
3/4 C. Dutch-process Cocoa Powder
1/2 C. Droste Cacao
2 1/2 C. Sugar
2 1/2 tsp Baking Soda
1 1/4 tsp Baking Powder
1 1/4 tsp Salt
Measure wet ingredients one on top of the other into a 4 C. measuring cup and give a quick stir.
1 1/4 C. Milk
1/2 C. + 2 Tbl Vegetable Oil, I use Canola
1 1/4 C. Warm Water
2 eggs + 1 Egg Yolk
Preheat oven to 350F. Line 3 muffin tins with paper liners leaving 1 corner empty (will make 33) OR prepare (2) 8" cake pans. Butter pans, insert parchment circle on bottom,butter again and lightly dust pan with flour. Discard excess flour.
Using the paddle attachment, add wet ingredients to the bowl and mix on a low setting until smooth, about 3 minutes. If you over mix you will have large holes (tunnels) in your cake. Ladle cupcakes 3/4 full or divide between cake pans. Cupcakes will bake in about 20-25 minutes. Cakes will take about 45 minutes. In both cases, once cake is fragrant, test with a toothpick and if it comes out clean, cake is done. Let cool on wire rack for 30 minutes and then remove from pan and let cool completely before trying to decorate.