Preheat the oven to 180°C (350°F).

In a bowl, melt the butter in the microwave until completely liquid.

Combine the melted butter with smoked paprika, Italian seasoning, brown sugar, salt, pepper, garlic powder, onion powder, and red pepper flakes.

Pat chicken tenderloins dry with paper towels, then coat each in the butter and seasoning mixture.

Line a baking sheet with parchment paper and lightly coat with cooking spray.

Arrange seasoned chicken tenderloins in a single layer on the baking sheet.

Bake in the preheated oven for 25-30 minutes until the internal temperature reaches 165°F (75°C).

Remove from oven and let the tenderloins rest for 5 minutes before serving.