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.

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.

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.

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.

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

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

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

Flip burgers.

Add a little pile of onions on each burger.

Top with cheese.

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!

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.

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