Absolutely delicious Mexican Sweetbreads; Conchas are perfect for breakfast, snack or merienda and pair excellently with coffee, chocolate, milk and more!
In a mixing bowl, combine: the yeast, 3 tbsp of the flour and 1 tbsp of the sugar. Warm the milk to approx. 43°C (110°F) and slowly add it to the dry ingredients, stirring with a spoon or whist until all is dissolved. If the milk is too cold, the yeast will not properly activate, but if it is too warm, the yeast could die.
Cover the bowl with cling film and keep in a warm area for 20 minutes - the oven set to a low temperature (about 20°C/70°F) will suffice. In this time the mixture should rise to form a large sponge-like consistency.
Pour all the remaining flour onto the surface and form a crater in the centre, similar to making pasta. Pour the sugar and salt around the outside of the crater, and inside pour the sponge, vanilla and eggs (3 yolks, 2 whites).
Make sure the butter is softened so you can mould it with your fingers, but still intact and not melted and dice it. With one hand, mix the wet ingredients inside the crater and slowly incorporate the flour, sugar and salt with the other. About half-way through the incorporation of the flour, add the diced butter bit by bit and mix all the ingredients with both hands to form a dough.
The dough at this stage will be very sticky and you will likely feel an impulse to add more flower, refrain from adding any additional ingredients and continue to knead until the dough passes the windowpane test. This should take around thirty minutes to an hour and can be done in an electric mixer with the dough hook attached - however, the final conchas may be less airy if a machine is used.
Coat the inside of a large, clean bowl with oil and place the dough inside. Cover the bowl with cling film and prove in a warm place until the dough has almost tripled in size - this can take between an hour and forty minutes to two hours.
In a mixing bowl, sift the flour and icing sugar and carefully mix with the vegetable shortening to form a play-doh-like product. Measure and half the topping and separate the two halves in separate bowls.
To one topping, add the vanilla extract and incorporate well. To the other, add the cocoa powder. The cocoa powder tends to make the topping quite sticky and difficult to manage; do not be afraid to add more flour to make it easier to manipulate, however, any more sugar will make it stickier.
Lightly flour the surface and roll out the dough on top. Spread it out and fold it in half four times, spreading it out again each time - this is to release some of the air.
Cut the dough into balls of 65g, you should have about 14-16 depending on how well your dough proved. Fold and roll the balls into smooth spheres and lay well spaced out on an oven pan with parchment paper. Flatten the edges of each ball.
Lightly sift some icing sugar onto the surface, in place of flour, to manipulate the the toppings. Divide the toppings to suit how many balls of dough you have and roll the pieces into circles about the same size as the balls of dough.
Coat the balls of dough with some vegetable shortening and cover them each with topping, cup the balls to securely stick the topping the dough. Use either a concha cutter or a knife to cut the classic concha design on the top of each - like a seashell, concha is the Spanish word for seashell.
Prove in a warm place for approx. one hour.
Bake in a 165°C (325°F) oven for 16-18 minutes and leave to cool before enjoying with a nice cup of coffee!