These bars are an easy addition to the kitchen counter. Make ahead and enjoy them breakfast, lunch or dinner. They're not too sweet and what sugar there actually is balances nicely with the addition of knotweed, rhubarb, lemon, and strawberries.
1 1/2 cups all-purpose flour
1/3 cup of sugar
1 1/2 teaspoons baking powder
1 stick of unsalted butter, cubed and chilled
1 medium egg
1 Pinch of Kosher Salt
2 cups sliced strawberries, 1/2 inch thick
2 cups sliced rhubarb, 1/2 inch thick
2 cups of sliced knotweed, 1/2 inch thick
8 teaspoons cornstarch
3/4 cup granulated sugar (100 grams)
2 lemons, zested and juiced
1 cup all-purpose flour
3/4 Cup of rolled oats
1/2 cup granulated sugar
1/4 cup packed light brown sugar
1/2 tsp of kosher salt
1 stick of unsalted butter, cubed, then softened
Preheat the oven to 375F.
Prepare a 9x9 or 9x13 inch baking dish by lining it with greased parchment and buttering the sides.
For the Base Layer
Combine all of the dry ingredients and the lemon zest. Use a fork to cut in the chilled cubes of butter until the mix is clumpy, and the pieces of butter are the size of smashed peas. Beat the egg and add it to the mix, continuing to cut in until a handful of the mixture stays together when squeezed.
Transfer the mix to the prepared baking dish and press it evenly into the base.
Bake this layer by itself for about 20 minutes while you prepare the rest of the ingredients.
For the Middle Layer
Whisk together the sugar and cornstarch, then add the remaining ingredients for the middle layer and mix.
When well combined, transfer these ingredients to a small sauce pot and bring to a simmer for 60 seconds.
Remove from the heat and transfer it to the baking dish and spread it evenly over the warm base layer.
For the Top Layer
Again, combine all of the dry ingredients in a mixing bowl. Use your hands to mix in the softened butter. The mixture should clump coarsely and irregularly.
Sprinkle this mixture in an even layer over the contents of the baking dish and transfer to the oven.
Bake for about 1 hour ensuring that you rotate or switch racks in the oven so that the top layer becomes golden brown but does not burn.
Remove from the oven and allow to cool on the counter for several hours before portioning and refrigerating.
Notes on use***
Feel free to dig in while it is warm, just be careful not to burn yourself with a bubbling middle layer!