For the cake

• Preheat oven to 350°F. Butter a 9x13 baking dish and set it aside.
• In the bowl of an electric mixer, cream the butter and sugar until light and fluffy, 5 minutes. Add the eggs one by one, letting them incorporate after each addition. Once the eggs are incorporated, mix in the vanilla extract.
  12 tbsp unsalted butter, 1 ¾ cups white granulated sugar, 4 large eggs, 2 tsp vanilla extract
• Separately, combine the flour, baking powder, cinnamon, and salt. Alternately add the dry ingredients with the milk, beginning with the dry and ending with the milk. Do not over-mix after the milk is added. A few lumps are ok. Finish mixing with a spatula to ensure the bottom of the bowl is evenly mixed.
  2 ¼ cups all-purpose flour, 3 tsp baking powder, ½ tsp kosher salt, ½ tsp cinnamon, 1 cup whole milk
• Pour the batter into the prepared pan and bake in the preheated 350°F oven until the cake is golden and a skewer inserted into the middle comes out clean, 25-35 minutes. Once baked, remove the cake from the oven and cool.
• While the cake is cooling, combine the whole milk, dulce de leche, and Irish cream. Whisk until smooth. The dulce de leche may be hard to mix in. If so, use a blender to make the milk mixture smooth. With the cake slightly warm, use a skewer or fork to poke holes all over the cake. Pour the milk mixture over the warm cake slowly, allowing the milk mixture to be absorbed. A small amount of milk may be visible on top of the cake. Cover the cake and chill for 4-6 hours or overnight.
  1 cup whole milk, ¾ cup Irish cream liqueur, 1 14-oz can dulce de leche (can also use sweetened condensed milk)
• Once the cake has chilled, combine the heavy whipping cream, Greek yogurt, powdered sugar, and vanilla extract. Whip until the heavy cream is thick and holds stiff peaks, 2-3 minutes. Spread the whipped cream mixture over the cake and serve. The cake can be frosted and chilled overnight.
  2 cups heavy whipping cream, 2 tbsp Greek yogurt, ¼ cup powdered sugar, 1 tsp vanilla extract