This rhubarb polenta cake is a simple cake that heralds spring. The tartness of rhubarb shines against the moist, pleasantly crumbly, and grainy texture of polenta.
In a mixing bowl, whisk together flour, polenta, baking powder, baking soda, and salt. Set aside.
Trim rhubarb into batons to fit the pan. Cut any thick stems in half along the length.
Preheat the oven to 350 degrees F.
Grease a 9 inch round cake pan or spring form pan.
In a stand mixer, fitted with the paddle attachment, cream the butter and sugar together until pale and fluffy.
Add the egg, vanilla, and lemon zest and beat until well combined.
Add half the milk and half the flour mixture and beat until well combined, scraping down the sides as needed to incorporate any chunks.
Repeat with the remaining milk and flour mixture.
Scrape the mixture into the prepared cake pan, smooth the top with a palette knife.
Place the rhubarb batons on top.
Place the cake in the oven in the middle rack and bake for 30 minutes.
Remove the cake from the oven, sprinkle the sliced almonds around the edges and turbinado sugar on top.
Bake in the oven for an additional 20-25 minutes until a toothpick inserted in the middle comes out clean.
Remove the cake from the oven and allow to cool for 15 minutes.
Dust the cake with confectioners's sugar and serve immediately with vanilla ice cream.
The cake will keep in an airtight container in the refrigerator for up to two days.