With an almond-scented crust, a layer of fruit preserves, and a buttery oat crumble topping, these bakery-style Jam Bars are easy to make and irresistible to eat!
Visiting from Pinterest? This recipe post was originally published in 2015 and has been updated in 2018 with new photos. Same delicious recipe!
I have a real weakness for any kind of streusel, crumb, or crumble topping. Whether it’s NY Crumb Cake, Blueberry Crumb Muffins, or a Fruit Crumb Pie, my fork is there.
(Also, don’t leave me alone with any of those things, because I might just swoop in and steal a piece of crumb topping when no one is looking!)
That in mind, these Jam Bars with Oat Crumble Topping are one of my favorite desserts to whip up when I need something buttery and bakery-style without a lot of fuss. Wherever I take them, they’re always devoured.
Testing Jam Crumble Bars: Contractor Approved
The concept of this recipe was inspired by the Raspberry Streusel Bars in Joy of Cooking, which I’ve made a number of times over the years. A few summers ago, though, I was craving a jam bar with a topping more reminiscent of a summer fruit crumble.
So, I started playing.
Among other recipe changes, I added brown sugar to the topping and omitted the nuts, milk, and eggs. (Though, I kept the milk in the base layer.) The buttery oat crumble topping ended up being exactly what I was craving against the luscious, fruity jam.
I love the flavor that a hint of ground cardamom brings to the oat crumble, especially paired with the preserves, almond extract, and cinnamon. The cardamom can absolutely be omitted if it isn’t a flavor you love.
I actually tested this recipe out on a group of contractors working in our home during their lunch breaks. When, after the last batch, they asked to take the recipe home to their families, I knew we had a winner!
How to Make Jam Bars: One Bowl Recipe
Jam Crumble Bars are pretty simple to prepare. They’re one-bowl (technically, one big bowl and a small cup to combine the milk and almond extract.) You can also make them using a food processor.
While the base layer is baking, the crumble topping is prepared in the same bowl you used previously (no need to wash in between!).
The filling requires no effort other than opening a jar of preserves and spreading it onto the crust. Since it’s a dominant flavor, you’ll want to use a quality jam or preserve.
What Kind of Jam Should I Use for Crumble Bars?
You can use whatever flavor or brand is in your pantry and is your favorite!
I love Sarabeth’s preserves, and they’re what I use most often for this recipe. For the batch pictured in this post, I used her Strawberry Raspberry preserves for a sweet-tart flavor that we love. Other favorites for these jam bars are Sarabeth’s Blueberry Cherry, Strawberry Rhubarb, and Peach Apricot preserves.
Wondering the differences between jams, jellies, and preserves? Check out this article from Bon Appetit’s Basically.
Serving and Storing Jam Crumble Bars
I like to slice these jam bars into large-ish squares and dust them with powdered sugar before serving. The powdered sugar is optional, but I think it gives such a pretty finish to the bars, especially on a platter.
I make jam bars year-round, but I especially love them for summer, when I need a dessert that’s easily stored and transported. Pies, crisps, and crumbles are great, but when it comes to serving a crowd at a picnic, a pre-sliced, grab-and-go bar is always an attractive option.
The jam bars store well in airtight containers for a few days, so they’re convenient to make ahead. In my humble opinion, they improve in flavor after a day. Sliced, they also freeze beautifully for longer storage.
Jam Bars with Oat Crumble Topping
For the base
- 2 cups all purpose flour
- ⅓ cup granulated sugar
- ¼ teaspoon kosher salt
- ½ teaspoon baking powder
- ¾ cup unsalted butter (1-½ sticks) chilled and cut into small pieces
- 3 tablespoons milk
- 1 teaspoon almond extract
- 1-½ cups quality jam or fruit preserves
For the crumble topping
- 1-½ cups all purpose flour
- ½ cup light brown sugar , lightly-packed
- ¼ cup granulated sugar
- ½ teaspoon kosher salt
- ½ teaspoon baking powder
- ½ teaspoon ground cinnamon
- ⅛ teaspoon ground cardamom (optional)*
- ½ cup rolled oats (not quick-cooking)
- ¾ cup unsalted butter (1-½ sticks), chilled and cut into small pieces
- powdered sugar for dusting (optional)
- Preheat oven to 375 degrees F with rack in middle position. Line a 13x9x2-inch baking pan with parchment paper with a 2-inch overhang on the long sides. Lightly coat parchment with cooking spray.
Make the base
- In a large bowl, whisk together flour, sugar, kosher salt, and baking powder. Using a pastry blender, a fork, or two knives, cut butter into flour mixture until it appears sandy and forms fine crumbs. (See Notes for food processor instructions.)
- In a small measuring cup, stir together milk and almond extract. Pour over the flour mixture and combine until moistened throughout. Mixture will remain crumbly. For a tender shortbread base, don’t overwork dough.
- Press dough into the prepared baking pan in an even layer. Bake 12-15 minutes, until center is just set and edges are just beginning to turn light brown. Remove from oven to assemble bars and leave the oven on.
Make the oat crumble topping
- While the base is baking, whisk together flour, light brown and granulated sugars, salt, baking powder, cinnamon, cardamom (if using), and oats. Using the same process as you did for the crust, cut butter into the flour mixture until crumbly.
Assemble the bars
- Spread preserves over hot crust layer. Sprinkle crumble topping in an even layer over preserves (the crumble layer will be thick).
- Return to oven and bake 25-30 minutes, until crumble topping is light golden brown. Let stand at room temperature in the baking pan until completely cooled.
- Dust with powdered sugar, slice into bars, and serve.