Dulce de leche and vanilla cake

Ingredients

• 170 gram butter on room temperature (3/4 cup)
• 300 gram sugar (1 1/4 cup)
• 1 tablespoon vanilla extract
• 150 ml milk (0.6 cups)
• 480 gram all-purpose flour (2 cups)
• 1 tablespoon baking powder
• large pinch of salt
• 5 egg whites
• 80 gram butter on room temperature (1/3 cup)
• 150 gram powdered sugar (3/4 cup)
• 50 ml cream (0.2 cups)
• pinch of sal
• 1/2 tablespoon vanilla extract
• 3/4th can of dulce de leche
• optional: sugar stars for garnish