Prep this One-Bowl Oatmeal Jam Bars for Memorial Day Weekend for an easy, grab-and-go breakfast (recipe by @jessie sheehan ) These oatmeal jam bars are what your bar cookie dreams are made. They succeed at being both crispy and chewy, sweet and salty, and, yes, also fruity. The oats make them wonderfully toothsome. And although the bottom crust and topping are made from the same dough (you're welcome!), they taste as different as different can be.