Mix dry ingredients: In a medium bowl, whisk together the protein powder, cocoa powder, and almond or oat flour.
Break up any clumps so the batter turns silky.
Add the flavor base: Stir in the vanilla and a pinch of salt. If using espresso powder, add it now for a deeper chocolate note.
Work in the nut butter: Add the nut or seed butter and use a fork or spatula to blend it into the dry mix. It will look crumbly at first—this is normal.
Sweeten and hydrate: Pour in 1 tablespoon of maple syrup (or your sweetener of choice) and 1 tablespoon of milk.
Stir, then continue adding small splashes of milk until a thick brownie-batter texture forms. Aim for scoopable, not runny.
Taste and adjust: Add more sweetener if you prefer it sweeter, or more cocoa if you like it darker. Balance with a tiny pinch more salt if needed.
Fold in extras: Mix in mini chocolate chips, chopped nuts, or a swirl of nut butter.
Keep add-ins modest so the batter stays smooth.
Serve: Spoon into a bowl, top with flaky salt or a drizzle of warm nut butter, and enjoy immediately.