Ingredients: Cake Layer: 1/2 cup + 2 tbsp all-purpose flour 1/2 tsp baking powder Pinch of salt 3 tbsp unsalted butter, room temperature 1/4 cup + 2 tbsp sugar 1 tbsp vegetable oil 3/4 tsp vanilla extract 1 large egg 1/4 cup milk Espresso Mixture: 3/4 cup hot water 2 1/2 tbsp instant espresso coffee...