Prepare the Oven and Pans:

• Preheat your oven to 350°F (177°C). Line two 12-cup muffin tins with cupcake liners and lightly spray them with non-stick baking spray. Set aside.

Mix the Dry Ingredients:

• In a large mixing bowl, sift together the flour, cocoa powder, baking soda, baking powder, and salt. Set aside.

Melt the Chocolate Mixture:

• In another large bowl, combine the canola oil, butter, and chopped chocolate. Heat in the microwave in 30-second intervals, stirring well after each interval, until the butter and chocolate are fully melted and smooth. Set aside to cool slightly.

Beat the Wet Ingredients:

• In a separate large bowl, combine the granulated sugar, brown sugar, eggs, egg yolk, and vanilla extract. Beat until smooth and fully combined.

Combine Wet Ingredients with Chocolate:

• Gradually add the melted chocolate mixture to the sugar-egg mixture, whisking constantly to incorporate.

Fold in the Dry Ingredients and Sour Cream:

• Add the sifted dry ingredients in three additions, alternating with the sour cream. Begin and end with the dry ingredients. Gently fold the mixture, stopping as soon as you see a faint trace of dry ingredients.

Add the Hot Coffee or Water:

• Pour the hot coffee (or water) over the batter. Let it sit for 30 seconds, then gently fold it in until fully combined.

Assemble the Cupcakes:

• Scoop 2 tablespoons of batter into each cupcake liner. Press a peanut butter cup into the center of each, then cover with an additional 3 tablespoons of batter. The cupcake molds should be about two-thirds full.

Bake:

• Bake one tray at a time for 16–18 minutes, or until the cupcakes are puffed and a toothpick inserted into the center comes out clean or with just a few moist crumbs. Let the cupcakes cool completely before frosting.

Peanut Butter Frosting

Beat the Butter and Vanilla:

• In a large bowl, using a handheld mixer or a stand mixer fitted with the paddle attachment, beat the butter on medium speed until completely smooth. Add the vanilla and mix until combined.

Add the Sugar:

• Reduce the mixer speed to low and gradually add the confectioners' sugar, 1/2 cup at a time, ensuring each addition is fully incorporated before adding more.

Add Milk and Beat:

• Once all the sugar has been added, pour in the milk and beat on medium-high speed for 3–4 minutes until the frosting is thick and creamy.

Final Mixing:

• Fold in the creamy peanut butter, then beat the mixture on medium-high speed for 1 more minute. Scrape down the sides and bottom of the bowl to ensure everything is well combined. Transfer the frosting to a piping bag fitted with an open star tip.

Milk Chocolate Ganache

Prepare the Chocolate:

• Finely chop the milk or semi-sweet chocolate and place it in a small heatproof bowl.

Heat the Cream and Peanut Butter:

• In a small saucepan, warm the heavy cream over medium heat until it begins to boil. Stir in the peanut butter until smooth.

Combine and Mix:

• Pour the hot cream mixture over the chopped chocolate. Let it sit for 1 minute, then whisk until smooth and glossy. Stir in the salt.

Assembly

Frost the Cupcakes:

• Pipe a swirl of peanut butter frosting onto each cooled cupcake.

Drizzle the Ganache:

• Using a small spoon, drizzle the milk chocolate ganache over the frosting. Add as much or as little as you like.

Garnish:

• Decorate the edges of each cupcake with chopped peanuts. Press one or two peanut butter cups into the top of each cupcake for a final touch.

Serve and Store:

• Enjoy the cupcakes the same day for the best taste and texture. They can be stored, covered, at room temperature for up to 2 days.