For the blueberry-chia jam:

• 2 cups fresh or frozen (thawed) blueberries
• 3 tablespoons pure maple syrup
• 3 tablespoons lemon juice, from about 1 large lemon
• 2 tablespoons chia seeds
• 2 teaspoons lemon zest, from about 1 large lemon

For the crust and crumble:

• 2 cups old-fashioned oats, divided
• 1 teaspoon baking powder
• 1/ 2 teaspoon ground cardamom (or cinnamon)
• 1/ 4 cup natural almond butter
• 1/ 3 cup pure maple syrup
• 1 egg
• 2 tablespoons extra-virgin olive oil
• 1 teaspoon vanilla extract
• 2 tablespoons sliced almonds
• Flaky sea salt, to taste

Method

• Step 1

  Line an 8x8-inch baking dish with parchment paper. Set aside.

• Step 2

  For the blueberry jam: In a medium saucepan, combine blueberries, maple syrup, lemon juice, chia seeds and lemon zest. Bring to a boil over high heat, reduce heat to low and simmer for about 10 minutes, stirring frequently and using the back of a spoon to smash the berries to release their juices. The mixture will look thin. Transfer to a bowl and let cool completely. This step can be done ahead of time, refrigerated in an airtight container for up to 3 days until ready to assemble.

• Step 3

  For the crumble: Preheat oven to 350 degrees F. In a food processor, combine 1 3/4 cups oats (reserve remaining ¼ cup for later), baking powder, cardamom and salt. Blitz to a fine flour, about 1 minute. Alternately, blitz oats in a high-speed blender and then mix the dough by hand.

• Step 4

  In a medium bowl, whisk almond butter, maple syrup, egg, olive oil and vanilla. Add mixture to food processor and pulse until a thick dough forms. Scoop out about ½ cup dough for the topping. Add remaining ¼ cup oats. Use a fork to combine, set aside.

• Step 5

  Press remaining dough into the bottom of prepared baking dish in an even layer with a greased spatula. The dough will be sticky.

• Step 6

  Pour cooled blueberry jam onto crust into an even layer. Scatter with oat crumble, using your fingers to break it up into small lumps. Sprinkle with almonds and a little flaky salt.

• Step 7

  Bake for about 40-50 minutes until crumble top is firm and golden brown. Let cool completely before slicing into bars. Store in an airtight container on the counter for up to 5 days, or freeze for up to 3 months.