1. In a food processor, blend together gluten-free flour, ground almonds, Natvia 100% Natural Sweetener, baking powder, oat milk, bananas, egg, smooth peanut butter, and vanilla extract until a batter forms.
2. Transfer almost half of this mixture to a separate bowl. To one part, add the dark chocolate chunks. To the other, mix in the cocoa powder and extra milk.
3. In a 9x9-inch greased and lined baking tin, add spoonfuls of the mixtures, alternating around the tin until all the mixture is used. Use a knife to swirl the mixtures together.
4. Bake at 180°C for 30-40 minutes, or until the brownies turn golden and firm. Let them cool, then cut them into bars or squares.
5. Once cooled, place them on a wire rack. Whisk together the Natvia 100% Natural Sweetener, smooth peanut butter, and enough water to create a slightly runny paste. Drizzle this over each brownie bar. Sprinkle the no added sugar peanut butter cup pieces on top.

Indulge in the irresistible flavors of these brownies, which perfectly blend sweetness, creaminess, and chocolate goodness, all made even better with Natvia. Enjoy!