Preheat oven to 350 degrees. Line an 8 inch square baking pan with foil and spray with GFCF cooking spray.
In a large bowl, combine brown sugar, arrowroot, almond flour, baking soda, and oats.
Add the softened butter and mix with a pastry blender or your hands until it forms a crumbly mixture.
Press 2 cups of the mixture into the bottom of the prepared pan.
Spread the jam over the oat mixture not going within 1/4 inch of the edge.
Sprinkle the remaining crumb mixture over the top and lightly press into the jam.
Bake for 35 to 40 minutes or until lightly browned. Cool completely. Remove from pan using the foil as handles and use a spatula to remove to keep squares in tact.