One-bowl brownies that won't guess are gluten-free and vegan! These brownies are fudgy and decadent, thanks to three kinds of chocolate and a "secret" ingredient you likely have at home. No fancy gluten-free or vegan ingredients needed.
Mix wet ingredients: Add half the chocolate (3.5 oz), grapeseed oil, and ground flax to a small saucepan. Warm on the lowest heat, whisking frequently, until chocolate is almost melted. Add sugar, whisk until mixture loosens again and chocolate is fully melted. Slowly pour in coffee, whisking vigorously until smooth (about 30 seconds). Remove from heat.
Add dry ingredients: Add oat flour, almond flour, cocoa powder, arrowroot powder, salt, and baking powder. Whisk thoroughly, until well incorporated. Stir in the remaining half of chocolate (3.5 oz.
Bake: Line 1 (8 x 8-inch) baking pan with parchment (see note 5). Pour in batter. Bake until a toothpick comes out clean from the center of the pan, 22 to 25 minutes. Allow brownies to cool for at least 30 minutes before lifting from the pan. Cut into squares.
Notes
Semi-sweet chocolate: 50-65% cocoa recommended. If vegan, check the label to confirm it's dairy free.
Coffee: To make just enough coffee for this recipe, brew a ratio of 1 tablespoon ground beans to 1 cup hot water. Strain grounds before using liquid. Coffee should be room temperature (slightly warm is okay), but not hot or cold. If avoiding coffee, substitute it with an equal amount of room temperature non-dairy milk.
How to make oat flour: To make your own oat flour, add rolled oats to a high speed blender and blend until a fine powder. When making homemade oat flour, we prefer a blender - over a food processor - because it achieves a finer grind.
Arrowroot powder substitute: You can use an equal amount of cornstarch instead.
Baking pan: If you have an 8-inch square baking pan with removable bottom, use it (makes for easier removal). Otherwise a regular bottomed pan will work.
Measuring by weight: For the most reliable results, we recommend measuring by weight when baking. Ingredient weights are provided in metric. If you must go by volume (measuring cups), make sure to fluff, spoon, and level the flours, cocoa powder, arrowroot, etc. to avoid adding too much.