Preheat the oven to 350 degrees.

Combine the butter and sugar together in a large bowl. Add in the vanilla and egg, then set aside.

In another bowl, combine flour, oats, salt, and baking soda. Add the flour mixture to the butter and sugar mixture and combine well. The mixture will be crumbly!

Place 2 1/2 cups of the oat mixture into the bottom of a lined 9×13″ baking dish. Press the oat mixture evenly into the bottom of the pan and set aside.

In a microwavable bowl, melt the sweetened condensed milk, butterscotch chips, and salt together. Heat for 1 minute, stirring every 30 seconds, until the mixture has melted and is nice and smooth.

Pour the butterscotch mixture over the crust, then add the remaining oat mixture on top and gently press down to firm the bars up a bit.

Bake for 25 minutes, or until the topping is golden brown. Cool the oatmeal butterscotch bars completely before slicing into 2 inch squares, and don’t forget to brush your teeth afterwards!