Step 1: Preheat the Oven

1. Preheat your oven to 350°F (175°C). Grease an 8-inch square baking dish with melted coconut oil.

Step 2: Prepare the Batter

1. In a large bowl, combine the rolled oats, protein powder, baking powder, cinnamon, and salt.
2. In another bowl, mix the applesauce, almond milk, honey, and vanilla extract until well combined.
3. Pour the wet ingredients into the dry ingredients and stir until just combined.

Step 3: Create the Cinnamon Swirl

1. In a small bowl, mix the brown sugar and additional cinnamon together to create the cinnamon swirl mixture.

Step 4: Assemble the Cake

1. Pour half of the batter into the prepared baking dish. Sprinkle half of the cinnamon mixture over the batter.
2. Pour the remaining batter on top and sprinkle the rest of the cinnamon mixture on top. Use a knife to gently swirl the cinnamon mixture into the batter.

Step 5: Bake

1. Bake in the preheated oven for 25–30 minutes, or until a toothpick inserted in the center comes out clean.

Step 6: Serve

1. Allow the cake to cool for a few minutes before slicing. Serve warm or at room temperature.