Place the bag of chocolate chips in a microwavable safe bowl in microwave in 30 second intervals until melted.
Pour 1 tbsp of chocolate into each chocolate mold. Use a spoon to swirl the chocolate around and coat the edges. Make sure to spoon the chocolate up the sides until it makes a thicker shell.
Put the chocolate mold in the fridge for about 15 minutes or until it’s set.
Combine the unsweetened cocoa powder with the erythritol in a bowl.
When the chocolate is set, remove from the refrigerator and gently pop them out of the mold. You should have 6 spheres.
Heat a plate in the microwave for 30 seconds, and be careful as the plate might be hot.
Carefully take the open side of the sphere and place it onto the plate to melt off the uneven edges to create a smooth edging.
Cut each marshmallow into 4 pieces. Spoon 1 tbsp of the cocoa and erythritol mixture in 3 of the 1/2 chocolate bomb and add 8 pieces of marshmallows on top.
Connect 1 empty half chocolate bomb to 1 half that is full of the mixture and seal together. As the melted chocolate hardens, it will seal.
Heat up the left over chocolate in the microwave for 30 seconds intervals until it’s soft again. Pour it in a Ziplock bag and cut a tiny piece at one of the ends or use a pasty bag with a tip. Drizzle the melted chocolate over top of the hot cocoa bomb and allow to dry. You can also use a spoon to drizzle instead of a bag.