Pat the sirloin steak cubes dry with paper towels to help them sear properly and develop a good crust.

In a medium bowl, toss the steak cubes with 1 tablespoon of olive oil, kosher salt, black pepper, paprika, garlic powder, and onion powder until evenly coated.

Let the seasoned steak rest at room temperature for about 10 minutes while you prepare the firecracker sauce.

In a small bowl, whisk together the melted unsalted butter, minced garlic, hot sauce, brown sugar, soy sauce, crushed red pepper flakes, and fresh lime juice until smooth and combined.

Heat the remaining 1 tablespoon of olive oil in a large heavy skillet over medium-high heat until the oil is hot and shimmering but not smoking.

Arrange the steak cubes in a single layer in the hot skillet, leaving a little space between each piece so they sear instead of steam.

Sear the steak bites for 2 to 3 minutes without moving them, then flip and cook for another 2 to 3 minutes, or until browned on the outside and cooked to your desired doneness.

Reduce the heat to medium-low, then pour the firecracker sauce over the steak bites, stirring to coat all the pieces evenly.

Let the steak simmer in the sauce for 1 to 2 minutes, stirring occasionally, until the sauce slightly thickens and clings to the steak bites.

Remove the skillet from the heat and sprinkle the chopped fresh parsley over the firecracker steak bites before serving.