Start by whisking together lime juice, cola, hot sauce, kosher salt, black pepper, and garlic powder in a large bowl. Add the flap steak, ensuring it’s fully coated in the marinade. Cover and refrigerate for at least 4 hours, or leave it overnight for maximum flavor. This step tenderizes the meat and infuses it with bold, zesty flavors.
Preheat your grill to high heat. Sear the marinated steak for 4–5 minutes per side, aiming for a medium-rare center. Use a meat thermometer to check for an internal temperature of 125°F. Once done, let the steak rest for 10 minutes to lock in the juices before slicing.
Set your grill to medium-high heat. Brush the fresh corn with canola oil and grill for 6–8 minutes, turning occasionally, until evenly charred. Once cooled, cut the kernels off the cob and mix them with mayonnaise, sour cream, Tajin, cotija cheese, cilantro, and red onion. This creamy, smoky topping is the star of the tacos!
Heat a cast iron skillet over medium heat. Toast one side of a tortilla, flip it, sprinkle shredded Jack cheese, and fold it in half. Cook until the cheese melts and the tortilla is crispy. Repeat for all tortillas.
Fill each cheesy tortilla with sliced steak and a generous scoop of the elote corn topping. Drizzle the creamy elote sauce over the top and garnish with extra cilantro and Tajin. Serve immediately and enjoy!