YIELD: Makes 16 squares
For the jam: Place a small plate in the freezer for testing the jam. In a large deep skillet, add blueberries, honey, and lemon juice. Heat and stir until it reaches a rolling boil. Boil and stir until it thickens, 10 minutes. Add a small spoonful of the jam onto the plate in the freezer and let sit for 30 seconds. Tilt it. If it slides too fast, cook another 1-2 minutes and check again. If it moves slow, it is done. Test every 1-2 minutes and do not overcook. Remove from the heat and cool to room temperature.
For the bars: Preheat oven to 350F. Line an 8x8 square pan with parchment or grease with cooking spray.
In a large bowl, mix together the flour, oats, cinnamon, baking soda, and salt.
In another large bowl, beat together the butter, honey, and brown sugar until creamy, about 2-3 minutes. Beat in the egg and vanilla until incorporated, about 1 minute (it may look curdled). Gradually beat in the flour mixture.
Evenly spread no more than half of the dough into the bottom of the pan. Top with cooled blueberry jam. Top with the remaining dough.
Bake 30 minutes or until golden brown. Cool completely before cutting into squares.