In a medium bowl, combine the oats, almond meal, chopped pecans, brown sugar, cinnamon, and salt. Cut the cold vegan butter into small cubes and add to the dry mixture. Using your fingertips or a pastry cutter, work the butter into the dry ingredients until the mixture resembles coarse breadcrumbs with some pea-sized pieces of butter remaining—this creates those delicious crispy, buttery clusters as it bakes. Set aside while you prepare the fruit.

In a large bowl, combine the raspberries, sliced rhubarb, cane sugar, and vanilla extract. Gently toss until the fruit is evenly coated and the sugar begins to release the fruit's natural juices. I find that letting the fruit sit for just a minute or two helps distribute the flavor more evenly throughout the filling.

Preheat your oven to 350°F. Pour the fruit filling from Step 2 into a 9x13 inch baking dish (or similar-sized dish), spreading it into an even layer. Distribute the crisp topping from Step 1 over the fruit in an even layer, breaking up any large clumps as you go—don't pack it down, as you want it to stay light and crispy. Bake for 45-55 minutes until the top is golden brown and the fruit filling is bubbling around the edges. I like to check it at the 40-minute mark to ensure even browning.

Remove the crisp from the oven and let it rest for 10 minutes before serving. This cooling time allows the filling to set slightly while the topping stays crispy. Serve warm with your favorite dairy-free ice cream or coconut cream for an indulgent treat.