Preheat your oven to 350°F (175°C). Grease or line an 8x8-inch baking pan with parchment paper.
In a mixing bowl, combine almond flour, vanilla protein powder, oat flour, baking powder, cinnamon, and salt. Stir until well combined.
In another bowl, whisk together the applesauce, melted coconut oil, maple syrup, and vanilla extract until smooth.
Gradually add the wet ingredients to the dry ingredients, mixing until a batter forms. Fold in the diced apple and chopped nuts, if using.
Pour the batter into the prepared baking pan, spreading it evenly. Bake in the preheated oven for 20-25 minutes or until the edges are golden brown and a toothpick inserted into the center comes out clean.
Allow the blondies to cool in the pan for 10-15 minutes before slicing. Serve and enjoy these delicious high-protein apple blondies!
Notes
Note: These blondies can be stored in an airtight container at room temperature for a few days or refrigerated for longer freshness.