Preheat the oven to 350 degrees F (180 degrees C). Line the bottom of a 9-inch tart pan with parchment paper (make sure your tart pan has a removable bottom as well).
Start by preparing the rhubarb filling. In a medium bowl, toss the
Rhubarb (2 cups)
Granulated Sugar (1/4 cup)
Vanilla Bean Paste (1 tsp)
Instant Clear Jel Thickener (1 Tbsp)
until the rhubarb slices are evenly coated; set aside.
Next, prepare the shortbread crust. In the bowl of a stand mixer fitted with a paddle attachment, cream the
Unsalted Butter (1 cup)
Granulated Sugar (2/3 cup)
on medium speed until light and fluffy, about 3 minutes, scraping down the sides of the bowl as necessary.
Beat in the
Vanilla Bean Paste (1/2 Tbsp)
Salt (1/4 tsp)
and continue beating until well blended.
All-Purpose Flour (2 cups)
and mix on low speed, just until there is no dry flour left. Do not overmix.
Remove 2/3 of the shortbread dough and pat it into the bottom of the tart pan, being careful to evenly distribute the dough, press firmly into place.
Refrigerate dough for 10 minutes.
Prepare the crumble topping. Add the
Old Fashioned Rolled Oats (3 Tbsp)
to the remaining dough, using a fork or your fingers to make a coarse crumble mixture.
Remove the shortbread crust from the refrigerator and arrange the rhubarb on top. Top evenly with the Crumble Topping – you will not totally cover the rhubarb, this allows the steam from the rhubarb to escape during baking and prevents a soggy topping.
Set the tart pan on a baking sheet, and bake in the preheated oven for about 35 minutes, or until the top starts to turn pale golden. If the edges are starting to get too dark, you can place a pie crust shield on top for the last few minutes of baking or lay a sheet of foil loosely over the top for the second half of baking so that it doesn’t brown too much (again, allowing for the steam to release while baking).
Remove from the oven and cool for 15 minutes before releasing the bottom of the pan from the sides; finish cooling to room temperature.
Cut tart into slices, serve and enjoy! I like to serve this with Rhubarb Raspberry Sauce and sweetened whipped cream on the side; vanilla ice cream is also wonderful on top of warm slices!