Combine 1/2 cup chopped blackberries and 3 tablespoons REBBL Vanilla Spice Protein drink in a small saucepan over medium heat; bring to a boil, then simmer and stir for 3 minutes.
Mash the berries lightly, leaving some texture, and continue cooking 1–2 minutes more until the mixture thickens into a sauce; transfer to a small bowl and keep warm.
Rub or brush the waffle iron with 1 tablespoon coconut oil and preheat to the highest setting.
In a medium bowl, whisk together 3 tablespoons almond flour, 3 tablespoons tapioca starch, 1/2 tablespoon coconut sugar, 1/2 teaspoon baking powder, 1/2 teaspoon ground cinnamon, 1/8 teaspoon ground allspice, and a pinch of salt.
Add 3 tablespoons REBBL Vanilla Spice Protein drink and 1 tablespoon melted almond butter to the dry ingredients and whisk until smooth; the batter will be thicker than typical waffle batter.
Place the batter in the center of the hot waffle iron, spread slightly, close firmly, and cook until the waffle is crispy and cooked through.
Serve the cooked waffle topped with the warm blackberry sauce.