1-Preheat and Prep: First, preheat the oven to 350 degrees Fahrenheit and lightly butter a 9 by 9-inch square baking pan, optionally lining it with parchment paper for easy removal. Prepare the rhubarb by thinly slicing it and tossing with 1 tablespoon of flour to coat.

2-Mix the Batter: Stir 1 teaspoon of lemon juice into 1/2 cup of half and half and set aside. In a large bowl, cream 1/2 cup of unsalted butter and 1 cup of granulated sugar until fluffy and pale yellow, then beat in 1 large egg and 1 1/2 teaspoons of vanilla extract, scraping the bowl as needed. In another bowl, whisk together the remaining 2 cups of all-purpose flour, 2 teaspoons of baking powder, and 1 teaspoon of salt.

3-Mix the Batter: Add half of the flour mixture to the butter mixture and blend, then add the half and half mixture and mix well. Finally, add the rest of the flour mixture and combine just until incorporated, avoiding overmixing to keep the cake tender. Fold in the rhubarb gently.

4-Bake and Cool: Spread the batter evenly in the prepared pan and sprinkle with the additional 2 teaspoons of granulated sugar. Bake for 40-45 minutes until golden and a toothpick comes out clean or with moist crumbs. Allow the cake to cool before cutting for the best results.