In a mixing bowl, beat the softened butter and brown sugar until well combined. Add the egg and vanilla extract, then mix until smooth.

Gradually incorporate the flour, mixing as you go until a dough forms. Gently fold in the dark and milk chocolate chips.

Take small portions of dough and roll them into tiny balls between your palms. Place each ball into a cavity of a half-sphere silicone mold.

Bake in a preheated oven at 180°C (350°F) for 13 minutes, until the cookies are baked through.

Remove the cookies from the mold and set them aside. Wash and dry the mold thoroughly, then melt approximately 200 g of milk chocolate.

Spoon some melted chocolate into each cavity, spreading it to cover the bottom and sides partially. Place one baked cookie into each cavity, gently pressing it into the chocolate.

Transfer the mold to the freezer and leave it until the chocolate shells have set completely and become firm.

Carefully remove the chocolate cookie bites from the mold. Serve and enjoy these delicious little treats!