In a bowl, combine 1 cup of bread flour, 1 tablespoon of sugar, and 2 tablespoons of yeast with 1/2 cup warm water. Mix well and knead for 3 minutes. Let rest for 1 hour.

While the dough is resting, prepare the topping for the conchas. In a bowl, beat together 4 tablespoons vegetable shortening and 1 tablespoon lard for 5 minutes until the sugar is well incorporated and the mixture turns white. Add the flour. The topping should not be too soft or too hard. Divide the topping in half and add cocoa powder to one half.

After the dough has rested for 1 hour, add the remaining ingredients: eggs, lard, butter, vegetable shortening, sugar, and cinnamon. Beat well for 3 minutes, then add the remaining 2 cups of bread flour. Mix well and knead for 5 minutes until the dough no longer sticks to your hands and is soft and elastic.

Once ready, divide the dough in half, then into 8 pieces. Shape each piece into a ball and place on a baking sheet.

After placing all the dough balls on the baking sheets, cover each ball with the topping, pressing it down so it flattens at the edges and stays a bit thick in the center.

Once all the conchas have the topping, use a spatula to score patterns on top—either crisscross or fan shapes—to resemble a seashell.

When the conchas have doubled in size, about 2 hours, bake at 350°F (about 175°C) for 29 minutes, one baking sheet at a time.