To make the cupcakes, preheat the oven to 180C/350F/Gas 4. Line cupcake pans with 24 cupcake liners and set aside.
Using an electric handheld or stand mixer, place the cake mix, butter, milk, and eggs into a large bowl and mix until combined and smooth.
Use an ice cream scoop to divide the cupcake batter between the liners.
Bake for 20 minutes or until an inserted toothpick comes out clean.
Leave to cool in the pan for about 5 minutes before transferring to a wire rack to cool completely before decorating.
To make the peanut butter frosting, use an electric stand or handheld mixer and add the butter, peanut butter, powdered sugar, vanilla, and cream to the bowl.
Beat on medium speed until creamy and smooth and stiff peaks form. Transfer to another bowl and set aside.
To make the vanilla frosting, use an electric stand or handheld mixer and add the butter, powdered sugar, vanilla, and cream to the bowl.
Beat on medium speed until creamy and smooth and stiff peaks form. Transfer to another bowl and set aside.
To make the chocolate frosting, use an electric stand or handheld mixer and add the butter, cocoa powder, powdered sugar, vanilla, and cream to the bowl.
Beat on medium speed until creamy and smooth and stiff peaks form. Transfer to another bowl and set aside.
To decorate the cupcakes, place a large piping bag fitted with a star tip into a large cup and fold over the sides.
Scoop some vanilla frosting down one-third side, some peanut butter frosting, down the second-third side, and chocolate frosting down the final third. Twist and push down until the frosting starts to mix out of the tip. Set aside.
Pour the sprinkles into a bowl. Set aside.
Use a small ice cream scoop to place some vanilla frosting on top of each cupcake and then smooth into a thick disc.
Dip into the Easter sprinkles mix until well covered.
Pipe swirls of the tri-flavored frosting on top of each dome of frosting. Refill the piping bag as required.
Insert a Reese's Peanut Butter Easter Bunny into each frosted cupcake.
Enjoy and Happy Easter!