1cupBlueberry Rhubarb Jamsee notes for recipe link
If you have not prepared the jam, follow the instructions in this post. Once the jam is ready, follow the next steps.
Preheat the oven to 350 degrees F. Grease an 8x8 baking dish and set aside. Add 1.5 cups of the oats to a blender and blend until you have a fine oat flour. Transfer the oat flour to a mixing bowl and add the rest of the whole oats, sugar, baking soda, and salt. Add the butter, and using a pastry cutter or just your hands, mix the butter and oat mixture together until it's crumbly.
Press half of the mixture into the greased baking dish, and bake for 12 to 15 minutes until fragrant and lightly brown. Remove from oven and pour the jam on top. Use a spatula to spread it into an even layer. Press the rest of the oat mixture on top of the jam, and bake for 25 to 30 minutes until lightly brown.
Remove from the oven and let it cool completely before slicing into 9 bars. The jam will thicken up as it cools, making the bars stay together better.
Plan for longer prep time if you haven't made the jam in advance. You can keep the jam in the fridge for up to a week, or you can freeze the jam and make these bars at a much later time if desired.
Store the bars in an airtight container at room temp for up to a week.
Please note that the bars are intended to be slightly crumbly, like a rhubarb crumble.