In a microwave-safe mug, combine cottage cheese, all-purpose flour, brown sugar, baking powder, ground cinnamon, and a splash of vanilla extract. Stir until mixed into a thick batter.

Add in the egg (or flaxseed mixture) and melted butter. Mix until smooth and well-blended, without any dry pockets of flour.

Microwave on high for 1 minute, checking for doneness. The cake should rise and feel firm when pressed.

Remove from microwave, let cool for 1 minute, and enjoy directly from the mug or add toppings like yogurt or maple syrup.