Make the cookies: Preheat oven to 375° degrees. Combine rhubarb and 3 tablespoons granulated sugar in a small bowl.
Whisk together flour, baking powder, salt, and remaining 7 tablespoons granulated sugar in a large bowl. Cut in the butter with a pastry cutter, or rub in with your fingers, until mixture resembles coarse crumbs. Incorporate the cream until dough starts to come together. Drain the rhubarb then add it to the dough.
Using a #50 scoop, scoop dough onto a parchment or silpat-lined baking sheet. Sprinkle with sugar and bake until edges become golden, 11 minutes.
I made a glaze to add more flavor to the cookies. I do not have precise measurements but the glaze is essentially a rhubarb sauce with powdered sugar.
Make the glaze: Cook sugar, water, and lemon juice in a pot until sugar dissolves. Add chopped rhubarb to sauce and continue to cook until rhubarb is tender. Let cool then puree in a blender.
Add powdered sugar until the glaze reaches desired consistency.