Melted unsweetened chocolate is often one of the key ingredients to baking gooey brownies and decadent chocolate cakes. In a pinch, you can substitute unsweetened cocoa powder (not a sugary cocoa mix)—you just need to add butter, shortening or a flavorless oil like canola.
Melt butter or shortening in a double boiler over low heat, stirring continuously, or in a microwave for 10-second intervals, stirring in between each interval.
Stir the unsweetened cocoa powder into the melted butter or shortening until smooth.
Use as directed in the recipe.