Directions

1. Warm 2 tablespoons milk in a small bowl, sprinkle yeast evenly over milk. Let sit for 5 minutes, then stir to dissolve. Set aside. Spray an 8-inch-square pan with cooking spray and set aside.
   
2. In the bowl of a stand mixer fitted with a paddle attachment, beat 3 tablespoons of butter, 1 1/2 tablespoons sugar, and 3/8 teaspoon salt on medium speed until light and fluffy, about 3 minutes.
   
3. Add 1/2 egg and beat until incorporated, 1 to 2 minutes. Scrape down the bowl. Add flour in three additions and the milk/yeast mixture in two additions, beginning and ending with the flour. After each addition, beat on the slowest speed to combine, scraping the bowl occasionally.
   
4. After the final portion of flour has been incorporated, increase the speed to medium-low and beat for 5 minutes or until dough is smooth and slightly elastic.
   
5. Stretch the dough into the prepared pan. If the dough resists stretching, cover the pan and allow the dough to rest for 15 minutes. Cover loosely with plastic wrap and allow the dough to rise for 2 hours.
   
6. Shortly before the dough is done rising, combine 8 tablespoons of butter, 1 cup sugar, 3/8 teaspoon salt and corn syrup in the bowl of a mixer fitted with the paddle attachment. Beat on medium speed until light, about 3 minutes.
   
7. Scrape down the bowl; add the vanilla extract and 1 egg. Beat until combined. Add the milk and cake flour and mix to combine on low speed. Scrape down the bowl and give the mixture a final stir.
   
8. When the dough is done rising, preheat the oven to 350 degrees. Cover the dough with dollops of the topping. Spread topping almost to the edges, leave about a 1/2-inch uncovered with topping.
   
9. Bake for about 20 to 25 minutes, until topping is crisp and golden brown; do not overbake. Topping will melt and spread as it bakes. Let cake cool in the pans on a rack. Sprinkle with powdered sugar just before cutting and serving.