The sponge cake: ****BIRTHDAY CAKE**** 110gr cake flour 85gr sugar 1/8 tsp baking soda 1/2 tsp baking powder 80gr unsalted butter 1.5 egg white 1/2 tsp vanilla extract 60gr sour cream 60gr milk 25gr sprinkle A pinch of salt
****BIRTHDAY CAKE CRUMB**** 50 gr granulated sugar 10 gr light brown sugar 45 gr cake flour 1 gr baking powder (1/4 tsp) 1 gr salt (1/2 tsp) 10 gr rainbow sprinkles (1tbsp) 20 gr oil