Cupcakes

Preheat oven to 175°C (350°F). Line a 12-cup muffin pan with paper liners.

Mix wet ingredients: In another bowl, whisk oil, eggs, buttermilk, and vanilla extract until smooth.

Combine batter: Sift the dry ingredients into the wet mixture and stir until just combined. Do not overmix.

Fill muffin liners: Divide the batter evenly between the muffin cups, filling about ⅔ full.

Add peanut butter swirl: Drop 1 tsp of peanut butter on top of each muffin. Use a toothpick or knife to gently swirl it into the batter.

Insert peanut butter cups: Push half a peanut butter cup into the center of each muffin (it will sink while baking).

Bake for 18–22 minutes, or until a toothpick inserted near the edge (not the center with the peanut butter cup) comes out clean.

Cool completely before frosting.

Make the Frosting

In a small saucepan, heat the heavy cream over medium heat until it begins to bubble (do not boil).

Pour the hot cream over the white chocolate chunks in a heatproof bowl. Let sit for 1–2 minutes, then stir until smooth.

Add peanut butter and stir until fully combined.

Cover with plastic wrap and let sit at room temperature for 15 minutes to thicken slightly.

Transfer to a piping bag fitted with a star tip or frost with a spoon

Decorate the Muffins

Pipe the peanut butter ganache frosting onto cooled muffins.

Garnish with chopped peanuts and mini peanut butter cups.