Oat Bars with Rhubarb Ginger Jam & Koyo Berries

Jess Damuck is back with these deliciously spiced Oat Bars made with Rhubarb Ginger Jam & Koyo Berries! The naturally sweet jam has less sugar than store-bought varieties so you can taste the fresh fruit and its complexity. 

PRODUCE:

1 pound (454 g)
rhubarb (about 2 stalks)
1 pint (400 g) fresh strawberries
2-inch (5 cm) piece fresh ginger
1 lemon

PANTRY:

1 cup (180 g) plus 2/3 cup (60 g) coconut sugar
1¼ cups (140 g) old-fashioned oats
1 teaspoon cornstarch or tapioca or potato starch
1¼ cups (156 g) all-purpose (or gluten-free 1 to 1 all-purpose) flour
1 vanilla bean
Kosher salt
½ teaspoon ground cinnamon

DAIRY:

1 cup (2 sticks/226 g) cold unsalted butter, or vegan butter, plus more for the pan

MAKE THE JAM:

1. Chop 1 pound (454 g) rhubarb stalks into ¼-inch-thick (6 mm) pieces.

2. Hull and thinly slice 1-pint (400 g) Koyo Berries.

3. Peel 2 inches (5 cm) ginger and grate using a Microplane.

4. Combine the rhubarb, strawberries, 1 cup (180 g) of the coconut sugar, ginger, and the juice of ½ lemon in a medium pot.

5. Scrape the seeds of the vanilla bean into the pot and then bring it to a boil, cooking until the rhubarb is softened, about 10 minutes, then reduce the heat to a rapid simmer.

6. Cook until the jam thickens and the rhubarb dissolves, about 30 minutes. Let cool for at least 30 minutes before assembling and baking the bars.

7. Meanwhile, make the crust: Preheat the oven to 325º F (165ºC). Add 1¼ cups (140 g) oats to a rimmed baking sheet and toast until lightly brown, about 5 minutes.

8. Cut 1 cup (2 sticks/226 g) cold butter into pieces.

9. In a food processor, combine the remaining 2/3 cup (60 g) coconut sugar and 1 teaspoon cornstarch and process until powdered.

10. Add 1 cup (80 g) toasted oats, 1¼ cups (156 g) flour, and a big pinch of salt, and pulse until finely ground.

11. Add the butter and process until the mixture is crumbly but holds together.

12. Butter the bottom of an 8-inch (20 cm) square baking pan, line with parchment paper, and butter again.

13. Transfer half the dough to the pan and press firmly into the bottom with a measuring cup.

14. Use a fork to make a couple of prick marks around the dough square.

15. Bake until lightly browned, about 25 minutes, and let the crust cool slightly, about 10 minutes.

16. Assemble and bake: Bring the oven back up to 325ºF (165ºC). Spread the jam (you should have about 1½ cups/355 ml) over the cooled crust.

17. In a small bowl, combine the remaining dough mixture, ¼ cup (40 g) toasted oats, and ½ teaspoon cinnamon.

18. Scatter the topping over the bars, squeezing some of the mixture together to create clumps.

19. Bake until the topping becomes light brown, about 20 minutes.

20. Transfer to a rack to cool completely, before cutting into squares and serving. Store in an airtight container for up to 3 days.