These ooey-gooey treats taste like a twist between blackberry cobbler and a bar cookie. The recipe, which was created by the chefs at Blackberry Farm, an award-winning luxury hotel and resort in eastern Tennessee, is a wonderful way to show off tangy, in-season blackberries. Make this recipe in the height of summer, when berries are at their best. The crust recipe, made with light brown sugar, rolled oats, flour, and butter, doubles as a streusel topping that toasts up beautifully in the oven. (The crust can be made a day in advance. Press it into the pan, cover with plastic wrap, and refrigerate.) The filling, a simple take on blackberry jam, can also be made a day in advance. Warm the mixture on the stovetop or microwave before pouring over the crust to make sure it spreads evenly. “These oat bars are a Blackberry Farm classic,” says Sarah Steffan, executive chef of The Dogwood restaurant at Blackberry Farm. “The recipe changes a lot with the seasons—we do it with peaches, strawberries, apples, you name it. The secret? Lots of butter.”