To make the mix, combine the flour, sugar, powdered sugar, cocoa, and salt in a large bowl. Mix well. Transfer the brownie mix to an airtight container and store at room temperature for up to 3 months.
This equals 8 store bought boxes of brownies.
Preheat the oven to 350 degrees F. Grease an 8-inch square baking dish.
Combine 2 ½ cups of the brownie mix, ½ cup melted butter, 2 eggs, 1 TB vanilla extract, and 2 TB water in a bowl. Mix until smooth. Transfer the brownie batter to the prepared baking dish.
Place the baking dish in the oven and bake at 350 degrees F for 20-25 minutes or until the brownies are set. Remove from the oven. Cut into squares while still warm. If desired, sprinkle with powdered sugar.
Store the brownies in an airtight container.
