Follow these simple steps to create irresistible Ham and Havarti Cheese Sliders:

1. Preheat Oven: Start by preheating your oven to 350°F (175°C).
2. Prepare Pan: Grease a baking dish or line it with parchment paper for easy removal.
3. Slice Buns: Carefully slice the slider buns in half horizontally, ensuring they remain attached at the back.
4. Layer Ham and Cheese: Place a slice of ham on the bottom half of each bun, followed by a slice of Havarti cheese.
5. Combine Butter and Mustard: In a small bowl, mix the melted butter, Dijon mustard, garlic powder, onion powder, salt, and pepper.
6. Brush Mixture: Using a pastry brush, generously brush the butter mixture over the cheese and ham on each slider.
7. Add Topping: Sprinkle poppy seeds evenly over the top of the sliders for added flavor and crunch.
8. Cover and Bake: Place the top halves of the buns back onto the sliders. Cover the baking dish with aluminum foil and bake for 20 minutes.
9. Uncover and Crisp: After 20 minutes, remove the foil and bake for an additional 5-10 minutes until the sliders are golden brown and the cheese is melted.
10. Serve: Remove the sliders from the oven and let them sit for a few minutes before slicing them apart. Serve warm and enjoy!

This simple process will guide you through creating delicious Ham and Havarti Cheese Sliders that your family and friends will love.