Preheat your oven to 375 degrees.

Grease a 9x13 baking dish with butter or coconut oil. Set aside.

In a large bowl mix together the strawberries, rhubarb, lemon juice, sugar and arrowroot powder. Set aside and stir occasionally while you make the crust.

In the bowl of your stand mixer blend together gluten free flour, butter, coconut oil, vanilla, granulated sugar, brown sugar and salt until a crumbly mixture forms. 

Reserve 1 cup of the crumbly mixture in a dish for the topping.

Press the rest of the crumbly mixture into the greased 9x13 baking dish using your hand, the bottom of a measure cup or a glass. Bake at 375 degrees for 15-18 minutes until lightly browned.

Let the crust cool for 10 minutes.

Stir the fruit mixture and then pour over top of the crust. Sprinkle the crumbly mixture over the fruit mixture. Sprinkle the slivered almonds over top.

Bake at 375 degrees for 30-35 minutes. The crust will be browned and the fruit mixture will be bubbly around the edges when it's done.

Remove from the oven and let cool before slicing into bars.

I like to serve with vanilla ice cream or whipped cream.