Preheat your oven to 350°F. Lightly spray a standard 9×4 inch loaf pan with cooking spray.

In a large bowl, whisk together the cake mix, protein powder, and crushed iced animal crackers until evenly combined.

Add the eggs, Greek yogurt, applesauce, sugar, and water to the dry mix. Mix thoroughly until fully combined.

The batter should be thick, similar to a standard cake batter, but still pourable. If it looks too thick or pasty, add a small splash of water until you achieve the right consistency.

Pour the batter into the prepared loaf pan and use a spatula to smooth the top. Bake for 50–55 minutes.

The cake is done when the internal temperature reads about 190°F. If the top begins to brown too quickly (common with sugar-free mixes!), loosely tent the pan with aluminum foil for the last 10–15 minutes.

Cool the cake in the pan for 10 minutes, then carefully transfer it to a wire rack to finish cooling completely. Cooling fully improves the structure and texture, reducing any chance of gumminess.

Once the loaf is completely cool, whisk together your powdered sugar substitute and a small amount of milk until you have a thick, smooth icing. Drizzle the icing over the top and scatter with extra crushed animal crackers for garnish.