In a large bowl, mix together the flour, sugar, baking powder, eggs, oil, milk, and vanilla until smooth. Set aside.
3. Step
In a small pot over medium heat, melt the butter. Add the dulce de leche and stir until mixture comes to a boil.
4. Step
Immediately pour the dulce de leche mixture into a round baking pan.
5. Step
Layer the apples in a circular pattern with each one overlapping the other. Repeat until the entire bottom of the pan is covered.
6. Step
Pour the cake batter on top of the apples and spread the batter evenly on top.
7. Step
Bake for 25 minutes, then cool until bottom is slightly warm.
8. Step
Place a large round plate on top of the cake pan, then flip quickly. Give the cake pan a few pats to make sure the cake is released, then lift off the pan.
