Preheat oven to 400º F.

Arrange bacon on a rack placed on a foil-lined sheet pan.

In a small bowl, stir together brown sugar, 3 tbsp. of the espresso powder; sprinkle over bacon.

Bake the bacon until caramelized and cooked through, about 18-20 minutes.

Meanwhile, stir together the mayonnaise, adobo sauce, and the remaining 1 tbsp. Espresso powder.

Preheat the boiler and place the rack 4-5 inches from the heating element. Place the toasted bread slices topped with cheese on a sheet pan and broil the cheese-topped toast until melted.

Spread the adobo mayo on top of the cheese and top with bacon, spinach, and eggs.