Preheat the oven to 350°F. Cover a baking sheet with aluminum foil. Coat the foil with spray release or with oil. Lay down each of the pieces of salmon onto the baking sheet. Set aside.
Place the rhubarb, honey, apple cider, shallot, and about a teaspoon of black pepper into a small heavy-bottomed saucepan. Heat over medium-low heat until the rhubarb is cooked and begins to fall apart. Add a little additional apple cider if more liquid is necessary. Cook for about 30 minutes until the mixture has reduced down to a thick syrupy consistency.
Brush the salmon with the rhubarb lacquer. Place the baking sheet onto the center rack of the oven and bake for about 5 to 6 minutes or until the bacon is just crisp.