1Place the rhubarb and 1 cup of the sugar in a medium nonreactive saucepan over medium heat, stir to combine, and cook until the rhubarb releases some juices, about 5 to 10 minutes. Reduce the heat to low and simmer, stirring occasionally, until the rhubarb is soft and just starting to fall apart, about 25 to 30 minutes. Remove to a bowl and let cool.
2Combine the flour, remaining 1 cup sugar, baking powder, and salt in a large bowl. Grate the butter on the large holes of a box grater, add it to the flour mixture, and rub between your fingertips until the ingredients just hold together when squeezed, about 3 minutes. Add the yolks and combine until the dough forms large, fist-size chunks when squeezed, about 1 minute (the dough will be crumbly). Dump the dough on to a piece of plastic wrap, and shape into a flat disk. Wrap tightly, and refrigerate for at least 30 minutes.
3Heat the oven to 375°F and arrange a rack in the middle.
4Evenly crumble the chilled dough over the bottom of a glass 13-by-9-inch baking dish, then firmly press it into the dish using the bottom of a measuring cup. Sprinkle the chopped almonds over top and press them lightly into the dough. Using a slotted spoon, evenly spread the cooled rhubarb over the base. If you have any remaining syrup, pour up to 1/3 cup evenly over the top (try to avoid the very edges of the dish). Bake until the dough is brown and the rhubarb mixture is bubbly around the edges, about 35 to 40 minutes. Let cool completely before cutting into 2-inch bars.
Beverage pairing:Bugey Cerdon, Caveau du Mont July, France. These bars are missing a classic companion for rhubarb—strawberries—so why not add that element with the wine? Bugey Cerdon is a sweet, sparkling rosé from eastern France that is light, summery, and reminiscent of berries and honeysuckle.