You can also try jam, marshmallow topping, or hazelnut spread as a filling for these buttery grilled sandwiches.
Butter 4 slices pound cake. Place 2 slices, buttered side down, on a work surface. Top each with 1 1/2 teaspoons peanut butter and 1 tablespoon melted milk chocolate; top each with 1 slice pound cake, buttered side up. Heat a medium skillet over medium. Add sandwiches and cook, flipping once, until golden brown, about 3 minutes per side. Slice each sandwich into 4 pieces and serve warm.