Rosemary Aioli: In a food processer, combine mayonnaise, garlic, lemon juice, cayenne pepper, rosemary, salt and pepper. Process until smooth. While pulsing slowly, add oil in a slow, steady stream until incorporated.
Preheat grill to 350˚F. Place burger patty on grill, until desired doneness. Place 1 slice of cheese on burger to melt.
Split English muffin and toast.
Sandwich Build: Spread 1 tablespoon Rosemary Aioli on heel of English muffin. Top with 1 cooked burger patty with cheese. Top with 1 fried egg. Top with ¼ cup baby spinach. Spread 1 tablespoon Rosemary Aioli on crown of English muffin. Close sandwich with crown of English muffin.