Place the oat flour, rolled oats, melted coconut oil, peanut butter, applesauce, and pumpkin puree in a mixing bowl.
Use a hand mixer, a spoon, or your hands to combine the ingredients. The dough will be sticky.
Let the dough sit in the bowl for 15 to 20 minutes until it stiffens up.
Press or roll out the dough onto a flat surface until it is about 1 to 1½-inches thick.
Using a bowl rim, knife, biscuit cutter, or round cookie cutter, cut out as many circles as possible. This recipe makes three 4-inch layers with enough left over for two small treats formed into a ball.
Place the circles separately, not on top of each other, on a tray or plate and put them into the refrigerator until they are harder to the touch, approximately 30 minutes.
Spread peanut butter on top of 2 layers and Greek yogurt on top of 1 layer.
Stack the layers to make a layer cake with the yogurt frosted layer on top.
Top with blueberries, strawberries, or any dog-safe fruit.
Slice and serve.