Preheat and Prep: Preheat your oven to 400°F (200°C). Line a rimmed baking sheet with parchment paper or aluminum foil for easy cleanup.
Season the Fish: Pat the salmon fillets completely dry with a paper towel. Drizzle the tops with the olive oil and rub it in lightly. Evenly sprinkle the kosher salt, garlic powder, onion powder, and black pepper over each fillet, pressing the spices gently so they stick.
The First Bake: Place the seasoned salmon on your prepared baking sheet. Bake in the oven for about 8 to 10 minutes (depending on the thickness of your fillets).
Glaze it: Carefully remove the salmon from the oven. Brush a generous amount of your homemade [Rhubarb BBQ Sauce] over the top and sides of each fillet.
Finish and Serve: Return the salmon to the oven for another 3 to 5 minutes, or until the fish flakes easily with a fork and that beautiful rhubarb glaze is hot, bubbly, and sticky. Serve immediately!