Preheat your oven to 425°F (220°C). Line a muffin tin with paper liners or grease them lightly with butter or cooking spray.

In a large mixing bowl, whisk the flour, baking powder, salt, and ground cinnamon until well combined. Set aside.

In another bowl, whisk together the melted butter, creamy peanut butter, and brown sugar until smooth and creamy. Add the eggs, one at a time, beating well after each addition. Stir in the milk and Greek yogurt until fully incorporated.

Pour the wet ingredients into the bowl of dry ingredients. Use a spatula or wooden spoon to gently fold the mixture together until just combined. Be careful not to overmix—the batter should be slightly lumpy.

Gently fold in the chocolate chips until evenly distributed throughout the batter.

Place the muffin tin in the preheated oven and bake at 425°F (220°C) for the first 5 minutes. This initial blast of heat will help create those coveted muffin tops.

After 5 minutes, reduce the oven temperature to 375°F (190°C) and continue baking for an additional 13-15 minutes, or until the muffins are golden brown and a toothpick inserted into the center comes out clean.

Allow the muffins to cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely to room temperature.

These muffins can be stored on the counter for 4-5 days, in the refrigerator for up to 10 days, or frozen for up to 3 months. Simply thaw them at room temperature or gently reheat them in the microwave for a warm, comforting treat.