• Preheat oven to 350 °F (177 degrees C). Smear a small amount of butter into a 10-cup capacity Bundt pan, making sure to get into all the crevices. Dust with flour and tap out the excess.
• Sift together flour, baking powder, cinnamon and salt into a medium bowl and set aside.
  2-3/4 cups (344 g) all-purpose flour, more for dusting the pan, 1 tbsp. (22 g) baking powder, 1 tsp. (7 g) table salt, 1 tsp. (3 g) ground cinnamon
• In the bowl of a stand mixer or using a hand mixer, beat butter, sugars and vanilla on medium speed until light and fluffy, about 3 minutes. Best in whole eggs, one at a time and then egg yolks. Scrape down the sides of the bowl. Beat in Greek yogurt until combined.
  1 cup (227 g) unsalted butter, room temperature, more for greasing the pan, softened, 1 cup (200 g) granulated sugar, 3/4 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, 1/2 cup (143 g) whole milk, plain Greek Yogurt
• Reduce mixer to low speed and add flour mixture in three batches alternating with buttermilk. (Do not overmix here, just until combined.)
  3/4 cup (19 ml) buttermilk, whole if you can find it
• Spoon cake batter into prepared Bundt pan, smoothing the top and knocking the pan on the counter a few times to release any large air bubbles.
• Bake for 55 minutes or until a wooden skewer returns clean from the center of the cake.
• Transfer to a cooling rack and let sit for 10 minutes in the pan. Loosen the edges with a knife and invert the cake onto the rack, remove the Bundt pan and allow to cool completely.

Churro Cake Topping:

• In a small bowl, combine sugar and cinnamon. Working in sections, brush the cake top with melted butter. Hold the cake over the bowl and sprinkle the top with the cinnamon-sugar mixture, pressing to adhere.
  1/4 cup (50 g) granulated sugar, 1 tsp. (3 g) ground cinnamon, 2 tbsps. (28 g) unsalted butter, melted
• Drizzle as much or as little dulce de leche over the top of the cake. Serve with ice cream.
  dulce de leche sauce (your choice how much to drizzle over the top)