In a large pot add enough water to cover tomatoes and set over medium heat. While water comes to a boil, rinse tomatoes and remove stem; with a paring knife make a small X on the bottom of each tomato. Carefully add tomatoes to the hot water and boil for 5 minutes, remove from the heat, cover, and let sit for another 5 minutes.
Fill a large bowl with cold water and ice. Add the tomatoes to the ice water and give them time to cool off about 10 minutes. Add more ice if necessary.
Peel cooled tomatoes; start from the bottom up. The curled edges help make the peeling easier.
With your hand, crush the tomatoes, into a non-stick pot. If they are still too hot, use a potato masher. Add the cinnamon and cloves and over low heat, boil roughly mashed tomatoes for about 45 minutes, stirring frequently so they don’t stick to the bottom of the pot.
Strain most of the water out of the tomato puree but leave enough in the tomatoes so they are not dry. I usually drain about 1 ½ to 2 cups of liquid. Reserve about ½ cup of the tomato liquid; refrigerate to cool.
Remove the cinnamon and cloves from the tomatoes. Mash tomatoes again in the pot with a potato masher. Add sugar or piloncillo and cook uncovered for another 30 minutes. If needed add more sugar to taste.
Add the cornstarch to ½ cup of reserved cold tomato liquid and whisk until well combined. Add cornstarch mixture to tomatoes and continue to cook for about 15 minutes. Cook until the consistency is like preserves.
As the tomato preserves cool it will thicken.
Can as needed or use immediately.
Make empanada dough:
Mix the first 3 dry ingredients. Cut in the shortening with the dry ingredients. Works better if you use your hands. Add the eggs, milk and sugar. Continue to work in with your hands. Split the dough in half, wrap in plastic wrap and put into the refrigerator for about 20-30 minutes.
Take out one half of the dough and split it into 12 rounds of dough.
Preheat the oven to 350 degrees F.
Roll out one round of dough into a small round circle. Take a paring knife and cut off the edges creating a square. Add about one tablespoon of preserves on one half of the rolled out dough. Bring down the top corner and match it up with the bottom corner, creating a triangle. Seal off the edges of the dough by pressing down on the edges with a fork. This also makes for a pretty pattern when baked.
Continue doing this until you have used up all your rounds and the scraps of dough.
Remove the second half of the dough from the fridge and repeat.
Assemble flower-shaped empanadas:
Roll out one round of dough into a small round circle. Take a paring knife and cut off the edges creating a square. Add about one tablespoon of preserves directly in the middle of your square. Pull up the four corners of the dough and pinch together tightly at the center, making sure that all four corners won’t come apart. With your fingers, squeeze the outer tips of the dough, creating a seal so the preserves don’t escape during baking.
Brush each empanada with egg whites, sprinkle with sugar. Layer a large cookie sheet with parchment paper, place the empanadas on the parchment paper and bake for 15 minutes on the bottom rack in the oven.
If after 15 minutes you notice the tops are not brown, move the baking sheet to the broiler and let them brown for 30 seconds to 1 minute. Watch them carefully to make sure they don’t burn.