This recipe included one variation, but since I didn't find the batter sweet, I didn't bother making it:
For a less-sweet version, decrease sugar to 1/2 cup.
Flourless Chocolate Cupcakes
*makes 12 cupcakes*
6 oz bittersweet chocolate, chopped
2/3 cup unsalted butter, cut into pieces
4 egg yolks
2/3 cup granulated sugar
2 tbsp almond meal
1 tbsp unsweetened Dutch-process cocoa powder, sifted
1) Preheat oven to 350F.
2) Line muffin pan with foil liners.
3) In a microwave-safe bowl, combine chocolate and butter. Microwave, uncovered, on High for 60 to 80 seconds, stirring every 30 seconds, until butter is melted and chocolate is soft. Stir until smooth and chocolate is melted. Set aside and let cool slightly.
4) In a bowl, using an electric mixer, beat eggs, egg yolks, and sugar for 2 to 3 minutes or until thick, pale, and consistency of soft whipped cream.
5) Fold half of the chocolate mixture into egg mixture. Fold in remaining chocolate mixture. In a small bowl, combine almond meal and cocoa powder. Sift dry ingredient over top of batter and gently fold in until incorporated.
6) Scoop batter into prepared pan and place on baking sheet. Bake in preheated oven for 8 to 12 minutes or until tops of cupcakes are just puffed up. Let cool in pan on rack for 3 minutes. Serve the cupcakes directly in the foil liners placed on individual plates with a spoon for easy scooping.
Recipe from 125 Best Cupcake Recipes by Julie Hasson