Preheat oven to 350 degrees. Line muffin tin with desired liners and set aside.
In a medium bowl, whisk together your flour, baking powder and salt. Set aside.
In the bowl of your stand mixer, beat together your butter and peanut butter until smooth. Slowly add in the sugar and beat until fluffy.
Add in the eggs, one at a time followed by the vanilla. Be sure to scrape the sides of the bowl well!
Slowly add in the dry mixture, alternating with the milk to keep the consistency smooth. Once done, remove from the stand in fold in your chocolate chips.
Scoop into cupcake liners until about 2/3 full - should make 20 - 24 cupcakes total!
Remove from oven and let cool.
In a small saucepan, heat the heavy cream until lightly steaming, but not boiling.
Add in the chocolate chips and cover. Let sit for 3 - 5 minutes.
Slowly whisk the mixture until smooth. Set aside to cool until it thickens enough to set in a spoon - about 30 minutes.
In the bowl of your mixer, beat together your butter and peanut butter until creamy.
Slowly add in 2 cups of the powered sugar. Mix in the salt and vanilla.
Add in the remaining sugar and heavy cream until the frosting is smooth, but not milky.
To swirl your frosting and ganache, lay out a piece of plastic wrap. Scoop the peanut butter frosting into a vertical line about 1/2 inch thick on the plastic wrap. Do the same with ganache and alternate until you have 4-6 rows.
Roll up the frosting into a small log and slip it into a large piping bag. Cut the end of the bag and pull the frosting tip through the piping tip. Snip again and begin swirling!
Decorate with sprinkles and enjoy!