Preheat oven to 350 degrees F & line 12 muffin slots with silicone muffin liners.
Whisk together eggs and brown sugar, then whisk in milk, butter, and vanilla extract.
In a separate bowl, combine almond flour and baking powder.
Add the dry ingredients to wet and mix until well combined.
Add 3 tbsp batter in each muffin cup. Add 1-2 tsp cinnamon sugar filling, then top with 1 tbsp of batter and swirl to cover. Sprinkle remaining cinnamon sugar on top.
Bake for 21-23 minutes
Let cool completely, top with frosting of choice & enjoy!