- 2 Cups mixed berries (raspberries, blueberries, and blackberries)
- 1 package cinnamon crumb cake mix, preferably Krusteaz Cinnamon Swirl Crumb Cake & Muffin Mix
- 1 egg
- 1/2 Cup Greek yogurt
- 1/2 Cup water
- 1 Teaspoon lemon zest
Preheat oven to 350 degrees F.
Spray one round (or spring-form) 9-inch pan with non-stick spray.
Arrange mixed berries in an even layer in the bottom of the prepared pan.
Sprinkle evenly with half of the cinnamon-topping packet.
In a large bowl, combine cake mix, egg, Greek yogurt, water, and lemon zest. Stir until combined.
Spoon half the batter evenly over berries.
Sprinkle remaining cinnamon topping over batter.
Drop remaining batter in small spoonfuls over topping layer and spread to pan edge.
Bake 45–55 minutes, or until toothpick inserted into center comes out clean.
Let cake cool 20–25 minutes before carefully inverting the cake and cooling completely.