To make the mix, layer 3/4 cup all-purpose flour, 3/4 cup unsweetened cocoa powder, 1 cup granulated sugar, 1 cup packed light brown sugar, 1/2 teaspoon baking powder and 1/2 teaspoon salt in a 2-quart mason jar (or other similar jar with an airtight lid). You may need to compress the ingredients a bit to fit.
Place the lid on and store for up to 3 months at room temperature.
To make the brownies:
Preheat the oven to 350°F. Spray an 8x8-inch baking dish with nonstick baking spray and set aside.
Pour all the brownie mix into a large bowl and stir to combine.
Add 3/4 cup salted butter, melted and mix it in.
Add 3 large eggs and 2 teaspoons vanilla extract and mix everything together until smooth.
Pour the batter into the prepared baking dish and smooth out the top.
Bake for 35-40 minutes until a toothpick inserted into the center comes out mostly clean, you still want some moist crumbs and a little batter on the toothpick, but nothing wet. This ensures fudgy brownies.
Allow to sit at room temperature until cool. Cut and serve.
Notes
Please refer to my FAQ’s (Frequently Asked Questions) and ingredient list above for other substitutions or for the answers to the most common questions.
This mix makes 9 servings of brownies - stored in one jar. Not 9 jars of mix.