I am copying this recipe directly from Authentic Cuban Cuisine by Martha Abreu Cortina.
2 cups all purpose flour
3/4 cup vegetable shortening
3/4 cups sugar
1/4 tsp. salt
1/2 tsp baking soda
Guava paste (optional)
Mix all of the ingredients together completely. Make a roll and cut 1/2 inch thick slices to form the cookies. Press down on the slices with the plam of your hand. Dent the center of the cookie with your thumb and fill with guava paste if desired. Bake at 350F degrees for 20 minutes.
The only problem I had with this recipe is that I had to add more shortening. The recipe may be correct and my measuring skills may be off since it is very difficult to get shortening into a measuring cup without making a complete mess. If you have trouble getting the dough to stick, add another 1/4 cup of shortening. Also I wasn't ready to bake yet, so I wrapped my roll in plastic wrap and refrigerated for a couple of hours. The cookies were a hit.