Best Flat Top Smash Burgers

The Best Flat Top Smash Burgers with Grilled Onions

We consider ourselves burger connoisseurs over here, and this easy recipe makes the best flat top smash burgers with grilled onions you’ll ever eat.

We like these burgers with our absolute favorite Traeger Smoked Bacon, so if you like bacon on your burgers, whip up a batch before starting this recipe.

Now if you don’t have a griddle or a flat top grill, a cast iron skillet will get the job done. We have a Blackstone Flat Top Gas Grill that we love and use all the time. I love it for fajitas and grilled veggies, my 7th grader makes pancakes on it, and my husband’s favorite thing to make are these delicious flat top smash burgers with grilled onions.

The Best Flat Top Smash Burgers with Grilled Onions

You’ll need, and this is important, 80/20 ground beef. If the beef is any leaner, it isn’t as juicy and delicious.

Ingredients

  • 2 Pounds 80/20 Ground Beef
  • 1/8 tsp Ground pepper
  • 1/4 tsp Garlic Powder
  • 1/4 tsp Onion Powder
  • 3 Medium Onions, sliced
  • 3 TBSP Salted Butter, divided
  • Kosher or Sea Salt
  • 8 Slices American Cheese (or cheese of choice)
  • 8 Hamburger Buns

Directions

Mix ground beef, pepper, garlic powder, and onion powder in a bowl and divide seasoned beef into eight loosely formed 1/4 pound balls. Set aside.

The Best Flat Top Smash Burgers with Grilled Onions

Heat flat top skillet to medium high and lightly oil with canola oil (or other high smoke point oil), and add sliced onions and 2 TBSP butter.

The Best Flat Top Smash Burgers with Grilled Onions

As butter melts, make sure all of the onions are coated. Cook onions until brown and caramelized. When onions are done or close to done, move to one side of the flat top, making room for the burgers.

The Best Flat Top Smash Burgers with Grilled Onions

Cooking the burgers moves very quickly, so buckle up! Place burgers, four at a time, on flat top.

The Best Flat Top Smash Burgers with Grilled Onions

Immediately smash burgers. Using two spatulas crossed over each other, smash each burger until they are pretty thin.

The Best Flat Top Smash Burgers with Grilled Onions

Season with kosher or sea salt and let cook two to three minutes, or until the bottoms are crusty.

The Best Flat Top Smash Burgers with Grilled Onions

Flip burgers.

The Best Flat Top Smash Burgers with Grilled Onions

Add a little pile of onions on each burger.

The Best Flat Top Smash Burgers with Grilled Onions

Top with cheese.

The Best Flat Top Smash Burgers with Grilled Onions

Add a little bit of water to flat top and cover burgers with large glass lid to let that steam melt the cheese. You don’t want those burgers cooking too long!

The Best Flat Top Smash Burgers with Grilled Onions

Remove burgers and onions from flat top and add remaining 1 TBSP butter. Open buns and place face down on buttery flat top. Cook a minute, or until those bun faces are just brown.

If you precooked some bacon to go with these burgers, you can put the cold bacon on the flat top to warm it up.

The Best Flat Top Smash Burgers with Grilled Onions

Add your desired toppings to the burger, like maybe our favorite Traeger Smoked Bacon, and grab a napkin!

Yield: 8 Burgers

The Best Flat Top Smash Burgers with Grilled Onions

The Best Flat Top Smash Burgers with Grilled Onions

These are the very best flat top burgers!

Prep Time 15 minutes
Cook Time 25 minutes
Total Time 40 minutes

Ingredients

  • 2 Pounds 80/20 Ground Beef
  • 1/8 tsp Ground pepper
  • 1/4 tsp Garlic Powder
  • 1/4 tsp Onion Powder
  • 3 Medium Onions, sliced
  • 3 TBSP Salted Butter, divided
  • Kosher or Sea Salt
  • 8 Slices American Cheese (or cheese of choice)
  • 8 Hamburger Buns

Instructions

  1. Mix ground beef, pepper, garlic powder, and onion powder in a bowl and divide seasoned beef into eight 1/4 pound balls. Set aside.
  2. Heat flat top skillet to medium high and add sliced onions and 2 TBSP butter. Cook onions until brown and caramelized, and move to one side of the flat top, making room for the burgers.
  3. Place burgers, four at a time, on flat top.
  4. Immediately smash burgers. Using two spatulas crossed over each other, smash each burger until they are pretty thin.
  5. Season with kosher or sea salt and let cook about two minutes, or until the bottoms are crusty.
  6. Flip burgers.
  7. Add a little pile of onions on each burger.
  8. Top with cheese.
  9. Add a little bit of water to flat top and cover burgers with large glass lid to let that steam melt the cheese. You don't want those burgers cooking too long!
  10. Remove burgers and onions from flat top and add remaining 1 TBSP butter. Open buns and place face down on buttery flat top. Cook a minute, or until those bun faces are just brown.
  11. If you precooked some bacon to go with these burgers, you can put the cold bacon on the flat top to warm it up.
  12. Build burger with desired toppings and enjoy!


Notes

80/20 ground beef is a must in this recipe.

The Best Flat Top Smash Burgers with Grilled Onions

Instant Pot Mexican Shredded Beef

Instant Pot or Crockpot Mexican Shredded Beef is perfect for busy families! It is spicy enough to keep the adults happy but not too spicy for most kids. It is easy to prepare and cooks quickly in the pressure cooker or all day in the slow cooker, and is great in burrito bowls, in tacos, on a bun, or on top of a salad!

Instant Pot or Crockpot Mexican Shredded Beef is perfect for busy families! It is spicy enough to keep the adults happy but not too spicy for most kids. It is easy to prepare and cooks quickly in the pressure cooker or all day in the slow cooker, and is great in burrito bowls, in tacos, on a bun, or on top of a salad!

Mother’s Day Muffins with Mom

This morning I happily shared my 3rd grade daughter’s corn muffin and my 5th grade son’s blueberry muffin at Muffins with Mom even though I really wanted a coffeecake muffin, because the muffins were huge and we certainly didn’t need three.

That’s what moms do.