Raspberry Oatmeal Crumble Bars

unsalted butter, melted

granulated sugar

light brown sugar, packed

vanilla extract

all-purpose flour

old-fashioned whole-rolled oats (don’t use quick cook or instant, they’re finer and behave like flour and will make mixture too dry)

salt, optional and to taste

about 12 ounces raspberry preserves (I used about two-thirds of one 18-ounce jar with seeds, use seedless preserves if preferred)