Beat the sugar and eggs with a mixer to a thick cream.
Sift the flour and baking powder and beat again.
Pour the mixture into a suitable oven dish and bake at 356°F (180 °C) until ready.
After the layer cools, poke holes in it with a wooden skewer.
Boil the syrup and pour it over it. Let cool again.
Beat the sugar and sour cream using a spoon (not a mixer under any circumstance or it will get runny).
Smear the resulting cream over the cake and decorate as desired.
Leave it to cool for a few hours in the fridge.