In a medium pot, whisk together the water and tapioca starch. Add the honey and whisk until well mixed. Bring to a boil on medium heat, stirring occasionally. Once boiling, cook, stirring constantly, until thick, about 3-5 minutes.
Once thick, remove from heat and whisk in the vanilla. Let stand until ready to use.
While the sauce comes to a boil, stir together 1/2 cup + 2 Tbsp of the tapioca along with 1/2 cup of the almond flour, almonds, coconut sugar and a pinch of salt. Add in the melted ghee and use your hands to mix it in until small crumbs form.
Press 2/3 of the crumbs very firmly into the bottom of a 9x13 inch baking pan.
Toss the strawberries and rhubarb together in a large bowl, along with the remaining 1 Tbsp of tapioca starch and almond flour until well coated. Spread in an even layer over the crumbs.
Pour the honey syrup evenly over the fruit, making sure it's all covered. Finally, sprinkle the top with the rest of the crumbs, making sure to leave some large, chunky crumbs.
Bake until golden brown and bubbly, about 30 minutes. OPTIONAL: broil for 2-4 minutes, watching CLOSELY at it burns fast. Let cool for 20-30 minutes
*As with all gluten free baking, please weigh your flour to ensure results