Prepare the brownie batter according to the package directions. Spread evenly into the prepared pan and bake for 12 to 15 minutes, until just set. Let cool completely.
Once cooled, cut the brownie slab in half. Place both halves in the freezer for about 1 hour to firm up.
In a large bowl, stir together the softened ice cream, chopped Raspberry KitKats, and sprinkles until evenly mixed.
Spread the ice cream mixture over one brownie half. Top with the second brownie half and gently press to create a sandwich.
Freeze for at least 4 to 6 hours, or until fully firm. Slice into bars.
Finish with a drizzle of melted white chocolate and a sprinkle of extra Valentine’s hearts if you’re feeling festive.