There is a corner in my backyard that belongs to the rhubarb. Every year when I see the little leaves pop up after the last snow, I know spring has arrived. 
Rhubarb is a perennial that is eaten as a fruit, although botanically it is a vegetable. While usually cooked, I remember eating it raw as a child, dipping the long stalks into a bowl of sugar, one dip for every bite. It is very tart – an eye-squinting, mouth-puckering tartness.
A co-star in the classic strawberry-rhubarb pie, it is often paired with strawberries or other sweet fruits in cobblers, crisps, compotes or preserves.
Historically, rhubarb root was used medicinally (as a laxative) in China over 5,000 years ago. It’s use in cooking didn’t start until the 19th century, in Britain. It became wildly popular for use in desserts and wine prior to World War II, then quickly dropped out of favour, most likely due to sugar rationing.
A word of caution, the leaves of the rhubarb plant are toxic due to high concentrations of oxalic acid. Granted, one would have to eat at least 5 kg for it to be lethal in humans, but best not to test that. Keep pets away from the leaves as well.
Nutritionally, 1 cup of uncooked rhubarb contains 26 calories, 1.1g of protein, 0.2g of fat, 5.5g of carbohydrates, 2.2g of fiber, and 1.3g of sugar. It is a good source of Vitamins C and K, potassium and manganese. It is surprisingly high in calcium and also a good source of magnesium.
These vegan rhubarb bars are the perfect compliment of sweet and tart and are lovely with a cup of tea.
Vegan Rhubarb Crumble Bars
Ingredients
Crumble Crust/Topping
- 1 1/4 cups quick-cooking rolled oats
- 1 1/2 cups all-purpose or whole wheat pastry flour
- 3/4 cup brown sugar
- 1/3 tsp baking powder
- 1/4 tsp salt
- 1/2 tsp cinnamon
- 2/3 cup vegan butter, cubed eg/ Earth Balance baking sticks
Rhubarb Filling
- 4 cups diced rhubarb
- 1 lemon juice and zest
- 1/2 to 3/ /4 cup sugar adjust sugar to taste, some prefer more tart, others more sweet
- 2 1/2 tsp cornstarch
Instructions
Crumble / Crust Instructions
- Preheat oven to 375 degrees. Line an 8 X 8 pan with parchment paper that overlaps on two opposing sides to make lifting the baked bars out easier
- In a large bowl, mix together the oats, flour, baking powder, sugar, salt and cinnamon
- Using two forks, blend in the chopped butter cubes until the mixture resembles coarse crumbs (Alternately, you can use your fingers to do this, but they will melt the butter a bit more than forks will)
- Spread 2/3 of the crumb mixture into the bottom of the pan, pressing it down firmly into a crust
- Bake for 15 minutes until lightly golden
Rhubarb filling
- In a heavy saucepan, combine rhubarb, lemon juice, lemon zest and sugar
- Bring to a boil over medium heat, stirring frequently for approximately 10 minutes
- When the liquid has released and the rhubarb has softened, sprinkle and quickly stir in the cornstarch, stirring constantly until mixture has thickened
- Turn off heat and let mixture cool briefly.
To assemble:
- Pour warm rhubarb mixture over baked crust in pan
- Evenly sprinkle the remaining crumb mixture on top of the rhubarb layer
- Bake for 30 minutes or until the crumble is golden and the rhubarb bubbling at the sides.
- Let cool completely
- Lift out of pan using the parchment as handles
- Cut into squares and serve
- Store in the refrigerator for up to a week, or freeze for up to 3 months