1. Place a rack in upper-middle of oven and heat to 375 degrees. Lay two pieces of foil perpendicular to each other in an 8" square baking pan, with excess hanging over sides to form a sling, then coat with cooking spray.
2. Whisk oats, both flours, salt, baking powder, and cinnamon in a medium bowl. In a second medium bowl, whisk maple syrup, almond butter, oil, and almond extract until smooth, then add to flour mixture and stir until combined. Transfer 3/4 cup mixture to a small bowl and refrigerate, then add remaining amount to prepared pan; use wet hands to spread into an even layer, then press until firm and flat. Bake until evenly browned, 20 to 25 minutes.
3. Meanwhile, combine blueberries, sugar, cornstarch, water, and lemon zest in a medium saucepan over medium. Cook, stirring and scraping corners of pan frequently, until filling is bubbling and very thick, 10 to 12 minutes. Remove from heat and stir in lemon juice.
4. Pour filling over warm crust and spread into an even layer. Scatter pea-size pieces of reserved crumb mixture evenly over top, then return to oven and bake until topping is browned and filling is bubbling around edges, 30 to 35 minutes.
5. Transfer to a wire rack and cool 30 minutes, then use foil sling to lift bars out of pan and back onto rack; peel foil off sides of bars and let cool completely, at least 1 hour. Cut into squares and store in an airtight container at room temperature for up to 5 days.
Source: Hannaford fresh Magazine, January-February 2021