Heat the oven to 350°F. Line a rimmed baking sheet with a nonstick silicone baking sheet. Scatter the mushrooms on the prepared sheet. Spritz with nonstick spray then season with smoked paprika, garlic powder, salt, and pepper. Transfer to the oven and cook, stirring occasionally, until crisp, about 40 minutes. Remove to a rack to cool. Store in an airtight container in the refrigerator for up to 5 days.