Preheat oven to 350°F and line a 12-cup muffin pan with paper or silicone cupcake liners.
In a bowl mix together oats, flaxseed, pumpkin pie spice, baking powder and salt.
In a large bowl whisk together pumpkin, egg whites, vanilla, coconut oil and maple syrup until combined.
Dump dry ingredients into wet ingredients; mix well. Pour in almond milk and stir until combined.
Gently stir in your mix-ins (pecans, walnuts, raisins or chocolate chips).
Scoop mixture evenly into muffin cups using a ½ cup measuring cup. Batter should fill 9-10 muffin cups.
Bake 30-35 minutes or until the center of each baked oatmeal cup is set and a toothpick comes out clean. Let cool for about one hour before removing from muffin pan. The oatmeal cups will set as they cool and if you try to remove them from the pan too soon, they will fall apart.
Store cups in an airtight container in the refrigerator (for a week) or freezer (for 2-3 months). If you freeze them, thaw overnight in the fridge and reheat in a toaster oven or microwave for 30 seconds the next morning.
To serve, I like to cut them in half, reheat in the toaster oven and spread on a layer of almond butter. They can also be eaten at room temperature or straight from the fridge. They’re tasty at pretty much any temperature!
To store, place baked oatmeal cups in an air-tight container in the fridge for up to 1 week or freezer for up to 3 months.