In a microwave-safe bowl, melt the butter with the mozzarella cheese for about 30 seconds.

In a larger bowl, combine the almond flour, baking powder, and cream cheese. Add the melted mozzarella and butter mixture. Knead the ingredients well with your hands until a dough forms.

Crack the egg into the dough and mix thoroughly until all ingredients are fully incorporated.

Place the dough in the freezer for 30 minutes to firm up.

Place the chilled dough on a surface lined with parchment paper. Use a rolling pin to roll it out.

Shape the dough into a circle. Using a knife, cut the circle into triangle-shaped wedges.

Roll each triangle from the wider base towards the point to form the classic croissant shape.

Repeat the process until all the dough is used.

For a filled version, you can place a slice of cheddar cheese or smoked turkey on the wide end of each triangle before rolling it up.

Arrange the shaped croissants on a baking tray lined with parchment paper.

Brush the tops with a beaten egg yolk.

Bake in a preheated oven until the tops are golden brown and the croissants are fully cooked.