Preheat the oven to 325 degrees F (165 degrees C). Grease a 9x13-inch baking pan.

Beat sugar and eggs together in a bowl with an electric mixer. Beat in oil. Stir in cocoa and matzo cake meal, then stir in nuts (or use the nuts as a topping).

Bake in the preheated oven until top is dry and edges have started to pull away from the sides of the pan, 30 to 35 minutes. (See Cook’s Note.) Let cool completely before slicing.