• Preheat your oven to 350°F (177°C). Grease a 10-cup Bundt pan thoroughly with butter, making sure to coat all the crevices, then dust it with flour and tap out any excess. In a medium bowl, sift together the flour, baking powder, cinnamon, and salt; set aside. (2¾ cups (344 g) all-purpose flour, 1 tbsp. (22 g) baking powder, 1 tsp. (7 g) table salt, 1 tsp. (3 g) ground cinnamon) In a stand mixer bowl or using a hand mixer, beat the butter, granulated sugar, light brown sugar, and vanilla extract on medium speed until light and fluffy, about 3 minutes. Add the whole eggs one at a time, then beat in the egg yolks. Scrape down the sides of the bowl and mix in the Greek yogurt until fully combined. (1 cup (227 g) unsalted butter, 1 cup (200 g) granulated sugar, ¾ cup (150 g) light brown sugar, 1 tbsp. (15 ml) vanilla extract, 4 large eggs (200 g), room temperature, 2 egg yolks (33 g) from two large eggs, room temperature, ½ cup (143 g) whole milk/plain Greek yogurt) Lower the mixer speed to low and alternately add the flour mixture in three parts, alternating with the buttermilk, mixing just until incorporated—avoid overmixing. (¾ cup (19 ml) whole buttermilk if available) Spoon the batter evenly into the prepared Bundt pan and smooth the top. Tap the pan gently on the counter several times to release any large air bubbles. Bake for 55 minutes or until a wooden skewer inserted into the center comes out clean. Remove the cake from the oven and let it rest in the pan on a cooling rack for 10 minutes. Run a knife around the edges to loosen, then invert the cake onto the rack and remove the pan. Let the cake cool completely.

Topping:

• In a small bowl, mix the granulated sugar and cinnamon together. Working in sections, brush the top of the cooled cake with melted butter, then hold the cake over the bowl and sprinkle the cinnamon sugar evenly across the top, pressing gently so it sticks. (¼ cup (50 g) granulated sugar, 1 tsp. (3 g) ground cinnamon, 2 tbsp. (28 g) unsalted butter, melted) Drizzle the dulce de leche sauce over the cake to your preference. Serve alongside ice cream if desired.