Beat applesauce, brownsugar, oil, and eggs in large bowl at medium speed. For about 1 minute.
Stir in baking mix, pumpkin pie spice, and nuts. Pour into prepared pan evenly.
Bake for 25 minutes or until toothpick is clean when inserted. Cool
Prepare Browned Butter Glaze: Heat butter over low heat until golden brown; remove from heat. Beat in powdered sugar and vanilla. Stir in water, 1 teaspoon at a time, until smoothe and of desired consistency.
Spread on cooled cake. Cut into bars, about 3x1 inch.