Preheat the oven to 350°F (175°C) and lightly grease a small baking sheet with cooking spray.
Trim any visible fat from the chicken breasts and place them on the prepared baking sheet.
Bake the chicken breasts until they are cooked through and no longer pink in the center, about 20–25 minutes; an internal temperature should reach 165°F (74°C).
While the chicken bakes, slice the tomato, cucumber, and red onion.
In a large bowl, toss the spinach leaves with the sliced tomato, cucumber, and red onion until combined.
Divide the salad mixture between two bowls.
Slice each baked chicken breast and place the slices on top of each salad.
Top each salad with Jalapeño-Lime Hummus to taste and serve.