Preheat oven to 350º F. Spray 8 x 8 baking pan with non-stick pan spray.
In a large bowl mix together the oats, whole wheat flour, flax seed, sunflower seeds, chia seeds, brown sugar, baking soda, cinnamon, and almonds.
Cut butter into small chunks and, with the almond butter and milk, mix it into the dry ingredients with a pastry cutter or clean fingers till well-distributed throughout.
Measure out 1 1/2 c. of the mixture and pat it onto the bottom of the prepared baking dish. You will reserve the rest for the top of the bars.
Pour lemon juice and 1 1/2 c. of the blueberries into a small saucepan. Crush berries with a potato masher and heat on medium to medium-high to boiling, stirring frequently. Remove from heat and stir in the remaining blueberries (about 1/2 c.), cornstarch, and lemon zest. Spread the filling evenly onto the patted down crumbs in the baking pan.
Sprinkle the reserved crumb mixture onto the top of the blueberry filling and press it slightly onto the filling with your fingers or a spatula.
Bake at 350º F for 25-30 till crust is golden and berries are heated through. Remove from oven and cool completely before serving.