Pre-heat oven to 350F. Grease a 9x13” baking pan and line with parchment paper, leaving a 2-inch overhang on the long ends of the pan.

Lay out rhubarb stalks parallel to one other and trim the stalks to 12½”, to fit the length of your pan. Then cut each stalk lengthwise into thin (¼-inch) ribbons. (If your rhubarb is already quite thin, you might want to halve each piece lengthwise.)

In a medium bowl, whisk flour, cornmeal, baking powder, and salt.

In a large bowl, with an electric mixer on medium, beat butter and sugar until fluffy, 3-5 minutes, and add eggs one at a time, beating after each addition. Add rosewater and beat until well combined.

With the mixer on lowest speed, alternately add dry ingredients and buttermilk, beginning and ending with dry ingredients; beat until just combined. ⁣⁣⁣

⁣⁣⁣Transfer batter to prepared pan, smooth top (an offset spatula works well here). Place rhubarb stalks parallel to each other over the batter.

Bake in the middle rack of the oven for 25 to 35 minutes, or until a tester inserted in the centre comes out clean.

Enjoy with powdered sugar on top.⁣⁣