Gather Your Ingredients: Before you start, ensure you have all your ingredients measured and ready to go. Preheat your oven to 350°F (175°C).
Mix the Dry Ingredients: In a microwave-safe mug or a small ovenproof dish, combine the oat flour, coconut sugar, collagen (or protein powder), cinnamon, pumpkin pie spice, and baking powder. Mix well.
Add Wet Ingredients: Stir in the pumpkin puree, egg, and almond milk. Combine until you have a smooth batter.
Add Chocolate Chips: Gently fold in the chocolate chips, reserving some for topping if you like.
Bake to Perfection: Place your mug or dish in the preheated oven and bake for approximately 15 minutes or until the cake is set and a toothpick inserted into the center comes out clean.
Top and Enjoy: Once baked, remove your Pumpkin Spice Baked Oats Mug Cake from the oven. Sprinkle with extra chocolate chips if desired. Let it cool for a moment, and then dig in while it's warm and comforting.