Prep ingredients as instructed above.

Preheat & prep muffin pan: Preheat oven to 350°F (175°C). Line or lightly grease muffin cups.

Mix muffin batter: In a medium bowl, whisk together flour, granulated sugar, baking powder, baking soda, and salt. In a separate bowl, whisk together egg, milk, oil or melted butter, and vanilla extract. Pour wet into dry and stir just until combined. Fold in mini chocolate chips.

Make cinnamon swirl: In a small bowl, mix brown sugar, cinnamon, and melted butter.

Assemble muffins: Spoon muffin batter into the prepared cups. Add a bit of cinnamon swirl mixture to each muffin and gently swirl with a spoon or knife.

Bake muffins: Bake for 18–20 minutes, or until a toothpick inserted in the center comes out clean. Begin egg prep while muffins bake.

Boil eggs: Bring a small pot of water to a boil. Gently lower eggs into the water and boil for 5½–6 minutes. While they cook, prepare an ice bath. Transfer eggs to ice bath immediately after boiling, then peel carefully.