2 pieces of Styrofoam; 12 candy sticks; a pastry bag
For the cake: Preheat the oven to 350 degrees F. Line a quarter sheet tray with parchment paper and spray with nonstick cooking spray.
Combine the flour, cocoa powder, baking powder and salt in a large bowl. Reserve.
Combine the granulated sugar and butter in the bowl of a stand mixer fitted with the paddle attachment. Beat until light and fluffy. Turn the mixer off and scrape down the sides of the bowl.
Beat in the eggs one at a time. Slowly add the sour cream, milk and vanilla. Scrape down the sides of the bowl as needed. With the mixer on medium speed, gradually mix in the flour mixture.
Spread the batter onto the sheet tray and bake, rotating the pan halfway through, until a toothpick inserted into the middle of the cake comes out clean, about 20 minutes. Let cool completely on a wire rack.
For the cream cheese frosting: Beat together the cream cheese, powdered sugar, butter, vanilla and lemon juice in a stand mixer or with a hand mixer until light and fluffy. Set aside.
Place the cake into a food processor and pulse to crumble. Transfer to a bowl, then add 2 cups of the frosting and stir to combine. Take some of the cake and frosting mixture and roll into a ball, roughly the size of a golf ball. Insert a candy stick into the center. Place onto a parchment-lined sheet tray. Repeat with remaining cake and frosting mixture, to make about 12 pops. Place into the freezer to chill for 15 to 20 minutes.
For the decorating: Set up 2 double boilers with a glass bowl fit over the top of each. Add the dark chocolate to one bowl, and the white chocolate to the other. Gently melt the dark and white chocolate over the double boilers, stirring frequently to ensure the chocolate is not burning on the bottom of the bowls.
For the white chocolate eyeball cake pops: Dip half of the chilled cake pops into the white chocolate, rotating to make sure they are fully coated. Allow any excess chocolate to drip off. Place right-side up into a piece of Styrofoam and stick one candy eye into the center of the cake pop. Repeat with remaining cake pops, transfer to the fridge to chill for 10 minutes.
Scoop 1/2 cup frosting into a small bowl and add 2 drops red food coloring. Mix to combine, then transfer into a pastry bag. Cut a very small amount off the tip, then pipe squiggly lines coming out from the candy eyes to resemble red veins.
For the chocolate-dipped cake pops: Take the other half of the cake pops and dip into the dark chocolate, making sure to fully coat the cake and allowing any excess to drip off. Roll immediately in the black and orange nonpareils. Place right-side up into a piece of Styrofoam, then into the fridge to chill.