Preheat oven to 350 degrees.
Spread walnuts in a single layer on a baking sheet.
Bake for five minutes then stir. Bake an additional 5 minutes. Let cool
Spray a 9x13 baking dish with cooking spray. Line with parchment paper.
Combine butter, sugar, and evaporated milk in a heavy bottomed saucepan.
Bring to a boil over medium heat, stirring frequently.
Once at a full boil, continue boiling for 5 minutes, stirring continuously.
Remove from heat and stir in white chocolate chips. (I use a whisk to get out all the lumps.)
Stir in marshmallow creme and maple extract.
Stir in toasted walnuts.
Pour into prepared dish.
Let cool completely.
Cut into squares and serve. Top with additional toasted walnuts if desired.