Cream butter and sugar together. Beat in egg.Mix in baby foods.
Add dry ingredients and mix.
Spread batter into 9"x13" baking dish sprayed with non stick cooking spray.
Bake for 25 minutes, or until toothpick, inserted, comes out clean.
Allow carrot cake bars to cool completely.
While bars cool, beat frosting ingredients together.Spread over cooled bars.Sprinkle with chopped walnuts, if desired.
Allow frosting to set up slightly before cutting. You can speed this up by refrigerating the frosted bars for 15 minutes. Wipe knife after each cut for clean cuts.
Video
Notes
Store bars in the refrigerator in an airtight container or covered in plastic.