Start by preheating your oven to 350°F. Grease your cake tin or ramekin with coconut oil or a light cooking spray. This ensures your cake won’t stick and makes cleanup easier.
Grind your oats into a fine powder using a food processor. Combine the oats and baking powder in a bowl. Then, add peanut butter, applesauce, and the egg, mixing until the batter is smooth.
Pour the batter into your prepared tin and bake for 25 minutes. Check with a toothpick; it should come out clean. Let the cake cool completely before frosting to prevent melting.
Mash the blueberries and fold them into Greek yogurt until creamy. Spread the frosting on your cooled cake or between layers if you’re making a double-decker cake.
If stacking cakes, place frosting between layers. Finish with a few whole blueberries on top for a festive look. You can add dog-friendly treats as decorations too.