1/2 cup (1 stick) salted or unsalted butter, plus more for greasing the pan (see note)
3 oz. unsweetened Valrhona chocolate
3/4 to 1 cup granulated sugar
2 eggs
1/2 cup all-purpose flour
1/2 tsp. vanilla
1/4 cup cocoa

Preheat the oven to 350 Degrees. Grease an 8-inch-square baking pan. If you like, also line it with with waxed or parchment paper and grease that.

Combine chocolate and butter in a small saucepan; warm over very low heat, stirring occasionally. When chocolate is almost melted, remove from heat; stir until smooth. Transfer chocolate mixture to a bowl; stir in sugar. Beat in eggs, 1 at a time. Add flour and vanilla. Stir just until no traces of flour remain.

Pour into the pan; bake until set and barely firm in the middle, 20 minutes. Let cool on rack before cutting.

*For spicy brownies - add 1 tsp. cinnamon and 1 tsp. cayenne pepper