Creating Chocolate Peanut Butter Swirl Muffins can be a delightful experience if you follow these simple steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Line a muffin tin with paper liners or grease it with cooking spray.
2. Mix Dry Ingredients: In a large bowl, whisk together the flour, granulated sugar, cocoa powder, baking powder, and salt until well combined.
3. Combine Wet Ingredients: In another bowl, whisk together the milk, vegetable oil, eggs, and vanilla extract until smooth and creamy.
4. Mix Together: Gradually add the wet ingredients to the dry ingredients, stirring until just combined. Do not overmix; a few lumps are okay.
5. Prepare Peanut Butter Swirl: In a small bowl, microwave the peanut butter for about 15-20 seconds until it’s slightly melted. This will make it easier to swirl into the muffin batter.
6. Fill Muffin Tin: Spoon the chocolate batter into each muffin cup, filling them about ⅔ full.
7. Add Peanut Butter: Drop a teaspoon of warmed peanut butter on top of each filled muffin cup. Use a toothpick or knife to gently swirl the peanut butter into the batter, creating a marbled effect.
8. Optional Chocolate Chips: If desired, sprinkle semi-sweet chocolate chips on top for an extra chocolatey touch.
9. Bake: Place the muffin tin in the preheated oven and bake for 20-25 minutes, or until a toothpick inserted in the center comes out clean.
10. Cool: Remove the muffins from the oven and let them cool in the tin for about 10 minutes. Then transfer them to a wire rack to cool completely.

With these clear instructions, you’ll be on your way to enjoying a batch of mouthwatering Chocolate Peanut Butter Swirl Muffins in no time!