Pie with Guava

Grease a baking sheet with margarine and flour and set aside.
Sift the flour and set aside.
Beat the eggs and sugar until a fluffy dough forms. Add a little vanilla essence and / or lemon zest to taste (I add a little of both, to give it more flavor).
With a spoon, incorporate the flour and mix gently until it forms a uniform dough (do not use an electric mixer, but wrap it with the spoon).

Pour the batter into the reserved pan and bake in a preheated medium oven until golden brown and dry in the middle. Remove from the oven and, using a damp towel dusted with sugar, unmold the cake.
Spread guava jam over the surface of the dough.
Wrap the cake with the towel.