Preheat the oven to 350°F (175°C) and line a 9x13 inch baking pan with parchment paper.

Combine almond flour, coconut flour, salt, vanilla extract, maple syrup, and melted coconut oil in a large bowl. Mix until a crumbly dough forms.

Press about 3/4 of the mixture into the prepared baking dish and bake for 10-12 minutes until golden.

In a medium saucepan, mix strawberries, chopped rhubarb, lemon juice, maple syrup, and a pinch of salt. Simmer for about 7 minutes.

Dissolve tapioca starch in water and add to the fruit mixture. Cook for an additional 1-2 minutes until thickened.

Remove the crust from the oven and let cool slightly. Spread the fruit filling evenly over it. Mix remaining crust with cashews and crumble over the filling.

Bake for another 20 minutes until the topping is golden and the filling bubbles.

Prepare a glaze with melted coconut butter, maple syrup, vanilla extract, and water. Drizzle over the warm bars once baked.

Let cool in the pan for at least 2 hours then lift out using parchment paper and slice into squares.