This pound cake is pretty great on its own, but a sweet blueberry compote and tea-infused whipped cream help take this dessert to the next level.
In a small saucepan, heat the cream over low until just hot, about 2 minutes. Add the tea bags. Transfer to a bowl and cover. Refrigerate until the tea flavors the cream, at least 6 hours or overnight. Remove the tea bags. Pour the cream into a clean large bowl. Add the confectioners’ sugar and vanilla. Using an electric mixer, beat until soft peaks form. Transfer to a jar and cover. Pack with ice in a cooler. Shake before serving.
Preheat the oven to 350°. In a large bowl, whisk the flour, salt, and baking soda. Using an electric mixer, beat the sugar and butter on medium speed until light and fluffy, about 3 minutes. Add the eggs, one at a time, beating until blended between additions and occasionally stopping to scrape down the bowl. Add the lemon zest and juice, then the buttermilk and vanilla. (Don’t worry if the mixture looks curdled.) With the mixer running, gradually add the dry ingredients and beat until just blended. Pour the batter into a buttered and floured 2-inch-deep 9-inch square metal baking pan. Bake until a toothpick inserted into the center comes out clean, about 1 hour and 10 minutes. Let the cake cool completely in the pan on a wire rack. Cover.
Meanwhile, make the sauce: In a medium saucepan, bring 3/4 cup water, the blueberries, sugar, lemon juice, and vanilla to a low simmer over medium-low heat. Cook, stirring often, until the sauce is thickened and shiny, about 25 minutes. Remove from heat. Let cool to room temperature. Transfer to a jar with a lid.
To serve, slice the cake. Top with the blueberry sauce, whipped cream, and basil.