Whisk the cornstarch and water together until all the cornstarch has dissolved. (I just use a fork to mix—very easy.) Place the cornstarch mixture, berries, maple syrup, and coconut sugar in a medium saucepan over medium heat. Using a rubber spatula, stir the mixture as it cooks. Smash some of the berries against the bottom/sides of the pot as you stir, gently breaking them up. Bring to a simmer and allow to simmer for 2 minutes, stirring constantly. After 2 minutes, remove pan from the heat and allow to cool completely. The mixture will thicken as it cools. To speed up the cooling process, feel free to cover and refrigerate it after it slightly cools for at least 30 minutes at room temperature. I recommend making the berry filling in advance so it can cool completely. Berry filling can be cold or room temperature when you assemble the bars—you just don’t want it hot or warm.

Preheat oven to 350°F (177°C). Line the bottom and sides of an 8-inch or 9-inch square baking pan with parchment paper, leaving an overhang on the sides to lift the bars out (makes cutting easier!). Set aside.

Pulse the oats in a food processor or blender until they’re slightly broken up. (For whole oats, about 10 pulses. For quick oats, about 5-6 pulses.) Pour into a bowl and stir in the cinnamon, a pinch of salt, the almond butter, maple syrup, applesauce, and melted coconut oil. Mixture will be thick and wet.

Using the back of a flat spatula or a spoon, press about 3/4 of the crust/streusel mixture tightly and firmly down into the pan. Make sure it’s flat and very compact, which helps guarantee the bars will hold their shape. Spread cooled berry filling evenly on top.

Mix the sliced almonds into the remaining crust/streusel mixture. Sprinkle all over the top of the berry filling. Sprinkle 1 Tablespoon of oats evenly on top. (Helps soak up some moisture.)

Bake for 27-31 minutes or until the topping is lightly browned. Remove from the oven and place baking pan on a cooling rack. Allow bars to cool completely. After about 1 hour cooling at room temperature, you can place the pan in the refrigerator to help speed the cooling up. Lift the cooled bars out using the parchment paper overhang on the sides. Cut into squares.

Cover and store leftover bars in the refrigerator for up to 1 week.