1/2cuppeanut butter chips or mini chocolate chips (optional)
Instructions
Preheat your oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or grease well with nonstick spray.
In a large bowl, whisk together the peanut butter, oil, and brown sugar until smooth and well combined.
Add the eggs, buttermilk, and vanilla extract. Whisk until fully incorporated.
Add the flour, baking powder, baking soda, and salt directly to the same bowl. Gently fold with a spatula until just combined. Do not overmix.
Fold in peanut butter chips or chocolate chips if using.
Divide the batter evenly among the 12 muffin cups, filling each about 3/4 full. Let the filled tin rest for 5 minutes.
Bake for 18 to 22 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
Let muffins cool in the pan for 5 minutes, then transfer to a wire rack to finish cooling.
Notes
Store in an airtight container at room temperature for up to 3 days, or freeze for up to 2 months. For extra moisture, brush the tops lightly with melted butter right out of the oven.