1 1/3 cups all-purpose flour
1/2 cup sugar
1/2 cup brown sugar
1/2 cup cocoa
1 tsp. baking powder
1/4 tsp. salt
1/4 cup butter, softened
2 large eggs or 3 large egg whites
2 tsp. vanilla

icing sugar, for rolling

Preheat the oven to 350°F. In a medium bowl (or the bowl of a food processor) combine the flour, sugars, cocoa, baking powder and salt. Add the butter and blend with a fork, whisk or pastry cutter (or pulse the food processor) until well blended.
If you’re using a food processor, transfer the mixture to a bowl. Add the eggs and vanilla and stir until the dough comes together (you may need to use your hands for this) – at first it will seem like there isn’t enough liquid, but it eventually works! You may need to get in there with your hands – don’t be afraid to – you’ll need to roll the dough into balls by hand anyway.
Put some icing sugar in a shallow bowl and spray two cookie sheets with nonstick spray. Roll the dough into walnut-sized balls and roll the balls in icing sugar to coat; place an inch or two apart on the cookie sheets.
Bake for 12-14 minutes, until set around the edges but still soft in the middle. Transfer to a wire rack to cool. Makes about 2 dozen cookies.”