Prep the Spread: Start by filling the indentations of an ice cube mold with chocolate spread. Pop it into the freezer for at least one hour before you start baking.
Preheat the Oven: Preheat your oven to 180°C (350°F). This ensures even baking.
Melt the Butter: Melt the butter in the microwave or in a bain-marie and let it cool down.
Mix Wet Ingredients: In a large mixing bowl, whisk together the eggs and powdered sugar until fluffy. Gradually add the warm melted butter and mix well.
Combine Yogurt and Milk: In a separate bowl, mix the yogurt and milk together. Pour this mixture into the egg mixture, stirring as you go.
Mix Dry Ingredients: Sift in the flour, baking powder, and salt to the wet mix, and stir vigorously. Then, fold in the chocolate chips and add the vanilla extract until fully combined.
Fill the Muffin Molds: Pour the batter into muffin molds, filling each cavity about 3/4 full. Gently place a square of frozen chocolate spread in the center of each muffin.
Bake & Cool: Bake in the preheated oven for 15-20 minutes or until a toothpick comes out clean. Let cool before unmolding them.