Prep Bacon Preheat oven to 400°F. Line a 15x10-inch baking pan with foil or parchment. Place a wire rack on top of liner. Arrange bacon slices on rack.
Season and Bake In a small bowl stir together brown sugar and 3 tsp. of the espresso powder; sprinkle over bacon. Bake until bacon is caramelized and desired doneness, 18 to 20 minutes. Cool slightly on wire rack.
Make Aïoli For chipotle-coffee aïoli, in a small bowl whisk together mayonnaise, adobo sauce, and the remaining 1 tsp. espresso powder.
Broil Preheat broiler with rack 4 to 5 inches from heat. Place toasted bread slices on a baking sheet. Top with cheese slices. Broil bread slices until cheese melts, 1 to 2 minutes.
Assemble Sandwich Spread with aïoli and top with bacon, spinach, and eggs. If you like, drizzle with chili crisp.
