In this task, you will be presented with the directions of a recipe separated by "," and have to fill in the "___" which is a step that is missing from the recipe.

Cream butter and sugar thoroughly.,______,Add combined cocoa and flour; beat well.,Add nut meats.,Bake in buttered 9 x 13-inch pan at 350 for 20 to 25 minutes.,Cool; cut into squares before removing from pan.,May be frosted.
Add vanilla and eggs.