Preheat oven to 350°F (175°C)—grease and flour three 8-inch round cake pans.
In a bowl, whisk eggs and sugar until doubled in volume.
In another bowl, stir sour cream with baking soda, then add to the egg mixture and beat until incorporated.
Add dulce de leche and beat until incorporated.
Sift flour, baking powder, and salt. Stir into the batter until just combined.
Divide batter among pans. Bake for 16-18 minutes, or until a toothpick comes out clean.
Let cool for 10 minutes before inverting onto wire racks to cool completely.