Position a rack in the center of the oven and preheat it 350oF. Prep a round 8-inch cake pan by greasing and lining with parchment paper.
In a medium sized bowl, whisk together all-purpose flour, polenta, baking powder and salt.
In a large mixing bowl, combine finely grated grapefruit zest and white sugar. Use your fingers to rub the mixture together until it becomes fragrant.
With an electric mixer, whisk the sugar and eggs together until light and fluffy on medium-high speed, about 2 minutes. Scrape down the sides and bottom of the bowl as needed.
Next, with the mixer on medium speed, slowly drizzle in extra-virgin olive oil and mix until combined. Then, add sour cream, grapefruit juice and vanilla extract and mix until incorporated.
Sift in the dry ingredients and mix on the lowest speed until just combined. Do not overmix.
Pour batter into prepared cake pan and bake for 35 to 40 or until an inserted toothpick in the middle of the cake comes out clean. After 30 minutes of baking, if the cake is getting too browned, you can loosely tent it with foil.
As the cake is baking, make grapefruit simple syrup by combining sugar and grapefruit juice in a small saucepan over medium heat. Bring to a boil and stir until sugar has dissolved, about 3 to 4 minutes. Set aside to cool.
Once the cake is done, let it cool in the pan for 5 to 10 minutes. Then run a paring knife around the edge of the cake and invert it onto a wire rack. Flip it right side up and then use a toothpick or skewer and poke tiny holes all over the top of the cake. Brush the syrup all over the warm cake, including the sides of the cake. Cool completely and serve with fresh whipped cream. Enjoy!
Position a rack in the center of the oven and preheat it 350oF. Prep a round 8-inch cake pan by greasing and lining with parchment paper.
In a medium sized bowl, whisk together all-purpose flour, polenta, baking powder and salt.
In a large mixing bowl, combine finely grated grapefruit zest and white sugar. Use your fingers to rub the mixture together until it becomes fragrant.
With an electric mixer, whisk the sugar and eggs together until light and fluffy on medium-high speed, about 2 minutes. Scrape down the sides and bottom of the bowl as needed.
Next, with the mixer on medium speed, slowly drizzle in extra-virgin olive oil and mix until combined. Then, add sour cream, grapefruit juice and vanilla extract and mix until incorporated.
Sift in the dry ingredients and mix on the lowest speed until just combined. Do not overmix.
Pour batter into prepared cake pan and bake for 35 to 40 or until an inserted toothpick in the middle of the cake comes out clean. After 30 minutes of baking, if the cake is getting too browned, you can loosely tent it with foil.
As the cake is baking, make grapefruit simple syrup by combining sugar and grapefruit juice in a small saucepan over medium heat. Bring to a boil and stir until sugar has dissolved, about 3 to 4 minutes. Set aside to cool.
Once the cake is done, let it cool in the pan for 5 to 10 minutes. Then run a paring knife around the edge of the cake and invert it onto a wire rack. Flip it right side up and then use a toothpick or skewer and poke tiny holes all over the top of the cake. Brush the syrup all over the warm cake, including the sides of the cake. Cool completely and serve with fresh whipped cream. Enjoy!