Preheat your oven to 350°F (175°C). This ensures an even baking temperature for the sliders.
In a small mixing bowl, combine the melted butter, Dijon mustard, garlic powder, and a pinch of salt and pepper. Whisk until smooth and well blended.
Carefully slice the slider buns in half horizontally, keeping the top and bottom halves connected. Place the bottom halves snugly in a greased baking dish to create a sturdy base.
Start by layering half of the sliced ham evenly over the bottom buns. Make sure to cover the surface completely for a delicious bite every time. Next, place a generous layer of Havarti cheese slices on top of the ham, allowing the cheese to melt beautifully as it bakes.
Add the remaining sliced ham on top of the cheese, creating a hearty filling, then gently place the top halves of the buns over the stacked ingredients to complete the slider assembly.
Drizzle the mustard butter mixture evenly across the tops of the sliders, ensuring every bun gets a nice coating for flavor. Sprinkle poppy seeds generously over the slider tops for added taste and a delightful crunch.
Cover the baking dish with aluminum foil to retain moisture, and bake in the preheated oven for 15 minutes. This will help melt the cheese and warm the ham thoroughly.
After 15 minutes, remove the foil and bake for an additional 5-10 minutes, or until the cheese is bubbling and the tops are a golden brown, indicating a crispy finish.
Once baked, remove the dish from the oven and allow it to cool for a few minutes. Gently lift the sliders from the dish with a spatula, being careful not to break apart the components.
Garnish the sliders with fresh arugula or spinach for a burst of color and freshness. Slice the sliders for easy serving, and enjoy the melty, savory goodness!
Notes
Arrange the sliders on a platter and serve with a side of dipping sauces like honey mustard or barbecue for an added kick!