Cream butter, sugar, egg, and vanilla well. Add flour baking soda and baking powder and mix till crumbly. Pat into a 9x13" pan that has been sprayed with a non-stick spray. Press down till the crust is smooth and uniform. Bake at 350 degrees for 18 to 20 minutes or until light golden brown. Remove from oven and let cool for 10 minutes.
While the crust is cooling, mix 1 cup of the chocolate chips with ½ of the can of sweetened condensed milk. Over medium-low heat, melt and stir until it's creamy. Remove from heat, stir in remaining cup of chocolate chips, sweetened condensed milk, egg, vanilla, and nuts. Stir till creamy and smooth.
Spread over cookie crust and return to 350 degree oven. Bake for 22 to 24 minutes until set. Remove from oven and set on a cooling rack. Gently press candy corn into crust, just lightly.
Place vanilla chips and oil in a zip-top bag and microwave for 1 to 1-1/2 minutes on half power. Press mixture together, mixing chips and oil together till smooth.
Snip the corner of the bag and drizzle over the pan of bars. After it cools, chill to set the swirly vanilla topping.
Recipe by Cheery Kitchen at https://cheerykitchen.com/bewitching-bars/