"Sweet, savory, tangy - this dessert is a balance of fall flavor and winter comfort. It is easily converted to a vegan dessert by omitting the egg white for 2 tablespoons of cornstarch in the fruit filling, and substituting butter with margarine in the crust. Add a dollop of whipped topping and enjoy! It's hard to eat just one :) Feel free to customize the amount of pretzel versus nut mixture. I do not always do it exactly, but either way it produces a savory, sweet, crunchy crust that is delicious. serve warm with whipped cream, whipped topping, gelato, or ice cream (either traditional vanilla or a non-dairy variety of ice cream tastes great)."
Preheat oven to 350 degrees F (175 degrees C). Grease 12 muffin cups.
Stir pretzel crumbs, butter, walnuts, brown sugar, maple syrup, cinnamon, and cardamom in a bowl until mixture is well combined and loose. Spoon pretzel mixture into the bottom of prepared muffin cups, filling them about 1/4 full. Press the crust down.
Beat egg whites in a large mixing bowl until frothy, and mix in raw sugar, self-rising flour, and vanilla extract to make a batter; stir in rhubarb and strawberries. Spoon fruit mixture over pretzel crust, filling muffin cups to the top.
Bake in the preheated oven until the fruit filling is bubbling and golden brown on top, about 30 minutes. Cool 10 to 15 minutes; serve warm.