Loaded Oatmeal Cookies

unsalted butter, softened to room temperature

packed light or dark brown sugar

 (50g) granulated sugar

large egg, at room temperature

vanilla extract

dark molasses

and 2/3 cups (140g) old-fashioned whole rolled oats

all-purpose flour, (measured correctly)

ground cinnamon

baking soda

salt

and 1/2 cups add-ins (I used butterscotch morsels, chopped peanut butter M&Ms, and chocolate chunks)