The perfect thing to take to a potluck is usually something you A) have all of the ingredients for, B) everyone likes, and C) easy to transport. These bars fit all of those qualifications PLUS they are easy to put together. They are also super versatile: the original recipe called for rhubarb. I've made it with mango, with pineapple, with berries ... pretty much most fruit would be a good option.
The original recipe came from smittenkitchen, because Deb is a genius. I've played with the recipe just a little bit.
Almond Rhubarb Picnic Bars
Depending on how you slice them, you can get 16 - 24 bars. You can double the recipe and bake it in a 9x13 pan.
Ingredients
Crust
1 cup (125 grams) all-purpose flour
1/4 teaspoon fine sea or salt
1/4 cup (50 grams) granulated sugar
1/2 cup (4 ounces or 115 grams) unsalted butter cold is fine
Filling
3/4 cup (75 grams or 2 1/2 to 2 3/4 ounces) sliced almonds ideally toasted and cooled
1 tablespoon (10 grams) all purpose flour
A few pinches of sea salt
6 tablespoons (75 grams) plus 1 teaspoon (5 grams) granulated sugar
5 tablespoons (70 grams) unsalted butter cold is fine
1 large egg
1/2 teaspoon almond extract 2 teaspoons brandy or another flavoring of your choice (totally optional)
1/2 lb. rhubarb (or your fruit of preference)
To finish
optional: Powdered sugar or 1/4 cup jam of your choice
Directions
Heat oven to 350 degrees F. Cut two 12-inch lengths of parchment paper and trim each to fit the 8-inch width of an 8×8-inch square baking pan. Press it into the bottom and sides of your pan in one direction, then use the second sheet to line the rest of the pan, perpendicular to the first sheet. This is going to make it very easy to remove the bars.
Make the crust: Combine the flour, salt and sugar in the bowl of a food processor. Cut the butter into chunks, and add it to the bowl, then run the machine until the mixture forms large clumps.
Note: it is not necessary to wash your food processor after the dough. Save yourself the hassle!
Transfer the dough to your prepared baking pan and press it evenly across the bottom and 1/4-inch up the sides. Bake for 15 minutes, until very pale golden. For the sake of speed, transfer to a cooling rack in your freezer for 10 to 15 minutes while you prepare the filing.
Make the filling: In your food processor bowl, grind almonds, 6 tablespoons sugar, flour and salt together until the nuts are powdery. Cut the butter into chunks and add it to the machine. Run the machine until no buttery bits are visible. Add any flavorings and egg, blending until just combined. Spread filling over mostly cooled crust.
Arrange the fruit: Sprinkle the fruit over the filling into a mostly-even layer. Don't worry about being too precise. You want to make sure each bite will have some sort of fruity goodness in it, but you also don't want to spend too much time on this because when the filling starts to bake, it will puff and potentially rearrange any design you may have intended.
Sprinkle fruit with 1 teaspoon granulated sugar.
Bake the bars: For 45 to 55 minutes, until they’re golden on top and a toothpick inserted into the almond cream underneath comes out cream-free.
Let cool in pan on a rack, or in the fridge, or even in the freezer. Totally optional but you can decorate the bars with a little powdered sugar, or warm some jam and brush it over for a glossier finish. These slice easiest when they are chilled. Enjoy!