Heat the oven to 350°F and line a baking sheet with parchment paper. The parchment keeps the cheese-based dough from sticking and makes cleanup much easier.
Put the mozzarella and cream cheese in a medium microwave-safe bowl and microwave for 30 seconds, stir, then microwave for 30 seconds more. The cheeses should look melted and stretchy, not bubbling, browned, or oily.
Mix in the almond flour and baking powder until the dry ingredients are mostly incorporated. At this stage the mixture will look shaggy and awkward, which is normal.
Add the beaten egg, then stir with a rubber spatula and finish kneading with your hands while the dough is still warm. It will feel stiff and messy at first, then turn into a smooth, uniform ball as the egg fully blends in.
Divide the dough into 6 equal portions. Even portions help the bagels bake at the same rate and brown more evenly.
Knead each piece briefly, roll it into a 7-inch rope, and press the ends together to form a ring. Rolling from the center outward makes the rope more even and less likely to crack.
Dip the tops in the sesame seeds and place the shaped bagels on the prepared baking sheet. If the dough feels tacky, slightly damp hands make shaping much easier.
Bake for 15 to 17 minutes, until the bagels are golden brown. You will smell a warm baked-cheese aroma when they are done, and the tops should look set and lightly browned.
Serve warm. The texture is chewiest right after baking, especially with a simple spread of cream cheese.