Spray a 9×13 pan with cooking spray and set aside.
In a large saucepan, under medium-low heat, melt the butter until completely melted. Add the marshmallows and stir occasionally until all the marshmallows have been melted.
Remove from the heat and add the extract, cereal, butterscotch pudding, and Skor bits. Mix until combined. Quickly transfer the mixture to the prepared pan. Press down to make an even layer. I used my hands just slightly dampened with cold water.
Let the mixture cool completely for at least an hour. Remove from pan and cut into squares.