Step 1: Prepare the Spicy Sauce

1. In a small bowl, mix mayo, ketchup, mustard, hot sauce, paprika, and garlic powder.

2. Stir until smooth and creamy.

3. Refrigerate until ready to use.

Step 2: Make the Jalapeño-Onion Mix

1. Heat 1 tbsp butter or oil in a skillet over medium heat.

2. Add sliced onions and jalapeños.

3. Sprinkle with sugar and a pinch of salt.

4. Cook, stirring occasionally, for 8-10 minutes until soft, golden, and slightly caramelized.

5. Set aside.

Step 3: Form & Season Burger Balls

1. Divide ground beef into 4 equal balls (don’t press them into patties yet).

2. Season with salt, pepper, garlic powder, and smoked paprika.

3. Keep chilled until cooking.

Step 4: Smash & Cook the Patties

1. Preheat a cast iron skillet or griddle over medium-high heat.

2. Add a bit of oil or butter, then place 2 beef balls in the skillet.

3. Using a spatula (with parchment paper if needed), press down hard to flatten into thin patties.

4. Cook for 2-3 minutes without moving them—edges should get crispy.

5. Flip and immediately top with cheese slices.

6. Cover briefly with foil or a lid to melt the cheese.

7. Repeat with remaining patties.

Step 5: Toast the Buns

1. While burgers are cooking, toast buns in a dry skillet or under the broiler until golden brown.

Step 6: Assemble the Burgers

1. Spread spicy sauce on the top and bottom buns.

2. Add lettuce or cabbage to the bottom bun if using.

3. Place the cheesy smash burger patty on next.

4. Top with a generous spoonful of the jalapeño-onion mix.

5. Add tomato slices or pickles if desired.

6. Top with the bun and press gently.