Preheat the oven to 375°F (190°C) and line an 8"x8" (20cmx20cm) baking pan with parchment paper.
In a large bowl, mix together the rolled oats, flour, sugar, lemon zest, baking powder and salt.
1 1/2 cups (150 grams) rolled oats, 3/4 cup (94 grams) flour, 1/2 cup (100 grams) brown sugar, 1 tablespoon lemon zest, 1/4 teaspoon baking powder, 1/4 teaspoon salt
Use your hands to incorporate the coconut oil and mix just until a dough forms. It should not be very crumbly, but should stick together.
2/3 cup (149 grams) coconut oil
Gently press a little less than two-thirds of the dough onto the bottom of the prepared baking pan.
Bake for 10-13 minutes or until the edges have just started to brown.
Meanwhile, prepare the filling. In a medium bowl, mix together the berries, jam, vanilla extract and salt. Spoon this over the still warm crust and sprinkle the remaining oat mixture over the berries.
2 1/2 cups (355 grams) fresh blueberries, 7 tablespoons (125 grams) raspberry, 1/2 teaspoon vanilla extract, pinch salt
Bake for another 22-27 minutes or until the top has lightly browned and the filling is bubbly.
Remove from the oven and let the bars cool completely. Refrigerate for 2 hours before cutting.
Store any leftovers in the refrigerator for up to 4 days. These can also be frozen.