4 tbsp. butter, plus more for muffin tins
1/3 cup sugar, plus more for muffin tins
1/3 c flour
1/4 t salt
8 oz bittersweet or semisweet chocolate, melted
Preheat oven to 400°F. Generously butter 6 cups of a standard muffin tin. Dust with granulated sugar, and tap out excess. Set aside. In bowl, cream the butter and granulated sugar until fluffy. Add eggs one at a time, beating well after each addition. With the mixer on low speed, beat in flour and salt until just combined. Beat in chocolate until just combined. Divide batter evenly among prepared muffin cups. Place muffin tin on a baking sheet; bake just until tops of the cakes no longer jiggle when the pan is lightly shaken, 8 to 10 minutes. Remove from oven; let stand 10 minutes. DO NOT OVERCOOK. To serve, turn out cakes, and place on serving plates, bottom sides up. Dust with powdered sugar.