Line a baking sheet with aluminum foil and spray with non-stick spray.
Combine mayonnaise, dijon mustard, tarragon, lemon juice and sugar together in a bowl. Mix well. Season to taste with salt and pepper. Set aside.
Place salmon on prepared baking sheet. Sprinkle with salt and pepper. Bake in preheated oven for 10 minutes. Remove from oven and spoon a dollop of sauce over the top. Return to the oven for 5 more minutes. Fish is done when it flakes easily.
Serve with remaining sauce on the side.
Notes
You will often find pin bones in salmon. It is a personal preference but I like to remove them before serving. I use a pair of tweezers. You can probably ask the fish monger at the seafood counter do to this for you as well. The best way to check the doneness of salmon is to use a meat thermometer and make sure it reaches 145 degrees. The easiest way to check if you don't have a meat thermometer is to press down on the salmon with a fork and flakes easily, it's done. This is best eaten the day that it is made. Nutrition information for estimation purposes only.