Mix together flour, baking powder, and salt in a quart jar. Layer remaining ingredients in the order listed. Press each layer firmly in place before adding the next layer. NOTE: Be sure to wipe out the inside of the jar with a dry paper towel after adding the cocoa powder, so the other layers will show through the glass.
Attach a tag with the following instructions: Brownie Mix in a Jar 1. Preheat the oven to 350 degrees F (175 degrees C). Grease and flour a 9x13inch baking pan. 2. Empty jar of brownie mix into a large mixing bowl, and stir to blend. Mix in 3/4 cup melted butter and 4 eggs. Mix thoroughly. Spread batter evenly into prepared baking pan. 3. Bake for 25 to 30 minutes in preheated oven. Cool completely in pan before cutting into 2 inch squares.