Double Chocolate Peanut Butter Cup Donuts

• 1 cup all-purpose flour
• 1/2 cup dark brown sugar
• 1/2 teaspoon salt
• 1/4 cup cocoa powder
• 1 teaspoon baking powder
• 1 teaspoon vanilla extract
• 1 egg large, at room temperature
• 2 tablespoons unsalted butter melted
• 1 tablespoon peanut butter creamy
• 1/2 cup milk type: chocolate almond milk or regular cow's milk
• 6 mini peanut butter cups chopped into 4 pieces each

For the Ganache:

• 1/2 cup heavy cream
• 4 ounces dark chocolate chips

Decoration:

• peanut butter cups mini, chopped