1 tablespoon loose-leaf black tea, plus more for garnish
1 tablespoon granulated sugar
Unsalted butter, softened, for greasing
1½ cups, plus 1 tablespoon, all-purpose flour, plus more for dusting
1½ cups rhubarb, cut into ½-inch pieces
1 cup plain Greek yogurt
1 cup granulated sugar
3 large eggs, at room temperature
1 teaspoon finely grated orange zest
½ teaspoon vanilla extract
½ cup olive oil
2 teaspoons baking powder
½ teaspoon ground cardamom
½ teaspoon kosher salt
Directions
Make the black tea cream: In a small bowl, combine the heavy cream and black tea, and chill for at least 4 hours or preferably overnight.
Make the rhubarb pound cake: Place a rack in the center of the oven and preheat it to 350°. Grease an 8½-by-4½-inch loaf pan with the softened butter and dust the pan with flour.
In a mixing bowl, toss the rhubarb with 1 tablespoon of flour; set aside.
In a large bowl, whisk together the yogurt, sugar, eggs, orange zest, vanilla and olive oil.
In a medium bowl, sift the 1½ cups of flour, baking powder and cardamom together, then stir in the salt.
Slowly whisk the dry ingredients into the wet ingredients. Gently fold the rhubarb into the batter. Pour the batter into the prepared loaf pan.
Bake the cake until the top is golden brown and a cake tester inserted into the center of the cake comes out clean, 50 minutes to 1 hour.
Strain the tea from the cream using a fine-mesh strainer. Using a rubber spatula, press down on the tea to release any remaining liquid; discard the tea solids. Using a stand mixer or a hand mixer, whip the cream, adding the tablespoon of sugar, until soft peaks form.
Serve the pound cake with the cream and garnish with crumbled black tea.