Preheat oven to 350°. Line an 8x8-in. baking pan with waxed paper, extending paper over edges of pan; set aside. Soak 2 Tbsp. chia seeds in ⅓ cup warm water in a small bowl for 5 to 6 minutes or until thickened, stirring occasionally.

Meanwhile, spray a small skillet with nonstick spray. Toast coconut flakes over medium heat for 3 to 4 minutes or until golden brown, stirring occasionally. Combine toasted coconut flakes, almond flour, almonds and salt in a medium bowl; set aside.

Microwave almond butter and coconut oil in a small microwave-safe bowl for 1 to 1½ minutes or until melted, stirring occasionally. Pour over almond flour mixture. Add in hydrated chia seeds; stir until combined.

For crust, evenly press 1½ cups almond mixture into prepared baking pan. Set aside remaining almond mixture for topping. Bake crust for 8 to 10 minutes or until lightly golden brown.

Meanwhile, soak remaining 3 Tbsp. ground chia seeds in remaining ½ cup water in small bowl for 5 to 6 minutes or until thickened, stirring occasionally.

For filling, stir together frozen blueberries, maple syrup and hydrated chia seeds in a medium saucepan. Cook over medium heat for 5 to 7 minutes or until thickened and berries begin to burst. Stir in lemon juice, vanilla and lemon zest; cook 1 minute more. Cool slightly.

Pour blueberry filling over almond crust. Top with remaining almond mixture. Bake for 15 to 18 minutes or until filling is bubbly and topping is light golden brown. Cool completely on a wire rack.

To serve, top with coconut chips, if desired. Use waxed paper to lift bars out of pan; cut into 16 bars. Store covered in refrigerator up to 5 days.