Prep the pan and oven. Line a 12-cup muffin tin and heat the oven to 350°F (175°C).
Grease the liners lightly for easy release.
Mix dry ingredients. In a large bowl, whisk almond flour, protein powder, coconut flour, baking powder, baking soda, salt, and cinnamon until evenly combined. Break up any clumps so the batter stays smooth.
Whisk wet ingredients. In a separate bowl or large measuring cup, whisk eggs, almond milk, Greek yogurt, melted coconut oil, vanilla, and sweetener until the mixture looks creamy.
Combine. Pour the wet mixture into the dry. Stir with a spatula just until no dry streaks remain. The batter will be thicker than traditional muffin batter but should be scoopable.
If it’s too thick, add 1–2 tablespoons of milk.
Prep blueberries. Toss blueberries with 1 teaspoon almond flour or protein powder. Fold into the batter gently to avoid streaking.
Fill the cups. Divide the batter evenly among the 12 muffin liners, filling each about 3/4 full. If using sliced almonds, sprinkle on top.
Bake. Bake for 16–20 minutes, rotating the pan once halfway. They’re done when the tops spring back and a toothpick comes out mostly clean (a few moist crumbs are fine).
Cool. Let muffins cool in the pan for 5 minutes, then transfer to a wire rack.
Cool completely for best texture and clean wrappers.
Enjoy or store. Eat warm or save for meal prep. The flavor settles and improves after a few hours.