Melt 1 tablespoon butter in a skillet over medium heat. Stir in the almonds, and cook until light brown and toasted, about 4 minutes.
Place the chicken breasts between two sheets of plastic wrap or waxed paper; flatten using a meat mallet or rolling pin. Season with salt and pepper to taste. Melt 3 tablespoons butter in a large skillet over medium meat; add the chicken breasts, and cook 1 minute on each side. Combine 1/2 cup almonds, cream, Dijon mustard, marmalade, and red pepper flakes with chicken, stirring to blend. Cook until sauce thickens, about 10 minutes. Serve chicken topped with sauce and remaining almonds.