Preheat the oven to 325 degrees
Grease and flour three 8x2 inch round pans, you could also use two 9 inch round pans.
In a medium size bowl, whisk the flour, baking powder, baking soda, and salt for 30 seconds. Set aside.
In a measuring cup add the milk, 1 Tablespoon oil and 1 Tablespoon vanilla. Set aside.
In the bowl of your mixer, add the butter and mix at medium speed until smooth. Gradually add the brown sugar and mix for 3 to 5 minutes until well blended and lightened in color.
Mix in ½ cup of the melted butterscotch morsels (as described above)
Add the eggs one at a time mixing until the yellow of the yolk disappears.
With the mixer on low speed, alternately add the flour mixture and the milk mixture, beginning and ending with the flour mixture - (3 additions of dry ingredients and 2 of wet ingredients).
Bake at 325 degrees for 22 - 25 minutes or until a toothpick inserted in the center comes out clean or with just a few crumbs attached. Let cool 5 to 10 minutes and turn out.