Given the task definition and input, reply with output. 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.

Melt butter.,In a bowl, mix eggs, sugar and cocoa.,Add butter to this mixture.,Stir.,Add flour; stir.,Add vanilla; stir.,______,Bake at 350 for 25 to 30 minutes.
Pour into 8-inch buttered and floured pan.