In a bowl, combine the soy sauce, sesame oil, brown sugar, garlic powder, and ginger powder. Add the sliced flank steak and marinate for at least 30 minutes, or up to 2 hours in the refrigerator for more flavor.

While the steak is marinating, prepare the spicy cream sauce by mixing the mayonnaise, gochujang, rice vinegar, honey, sesame oil, and a pinch of salt in a separate bowl. Adjust the spice level by adding more gochujang if desired. Set aside.

Heat a skillet over medium-high heat. Once hot, add the marinated steak and cook for about 3-4 minutes, stirring frequently, until the steak is browned and cooked through.

To assemble the bowls, divide the cooked rice among four bowls. Top each bowl with the cooked steak, shredded carrots, sliced cucumbers, and chopped green onions.

Drizzle the spicy cream sauce over the top of each bowl and sprinkle with sesame seeds for garnish. Serve immediately.