Line a cupcake pan with paper liners. Preheat oven to 350 degrees.
Stir dry ingredients together in large bowl. Set aside.
Heat Coke, cocoa, and butter in small saucepan on medium heat until butter is melted.
Whisk sugars into chocolate mixture until blended. Remove from heat and let cool.
Add egg to cooled chocolate and stir well.
Add chocolate mixture to dry ingredients and whisk together.
Add vanilla and stir.
Fill cupcake liners with 1/4 cup batter.
Bake 20-25 minutes or until knife inserted comes out clean.
Cool before filling.