Instructions

1. In a large pot, place the unopened can of condensed milk and fill the pot up with water so that the can is submerged and there is at least an inch of water on top of it.
2. Turn the heat to medium and half-cover the pot with a lid. Cook on this heat for 3-4 hours (the longer you cook it, the darker your sauce will be). If the water level gets too low, continue to refill the pot so that the can stays covered.
3. Let the can cool completely in the pot before opening. Store dulce de leche in the fridge and heat in the microwave when ready to use.
4. In a saucepan over medium heat, heat butter and milk just until butter is melted. Remove from heat and stir in vanilla. Let cool to just above room temperature.
5. While butter and milk and heating up, whisk 2 tablespoons sugar with the warm water in a small bowl until dissolved. Whisk in yeast and let sit 5 to 10 minutes until foamy.
6. In the bowl of a stand mixer, whisk remaining 6 tablespoons sugar with 4 cups of flour and salt until combined. Add butter-milk mixture, yeast mixture and eggs. Stir on low speed using the dough hook attachment until everything is loosely combined.
7. Add another 1½ cups of flour and continue to stir on low with the dough hook attachment until a smooth, but rather sticky dough forms (it will be a little stickier and looser than normal). Shape dough into a loose ball in bowl; cover bowl with plastic wrap. Place bowl in a warm place and let dough rise 1 to 1½ hours until doubled.
8. Meanwhile, in a small bowl, whisk sugar and cinnamon for the filling. Toss the sliced apples in this mixture until each slice is well-covered, and store in a tupperware until ready to use.
9. Punch down risen dough. Add remaining ¼ cup flour and knead into dough on a countertop. Let dough rest 5 minutes, covered with a clean kitchen towel. If you don\'t plan on making this right away, put the dough in a bowl and cover it in plastic wrap. Refrigerate it, taking it out about 30 minutes you plan on rolling it out.
10. When ready to roll, divide dough into 2 equal-sized pieces. On a lightly floured surface, shape one piece of dough into a rough rectangle. Roll out dough to a 20-by-12-inch rectangle.
11. Brush dough with half of the melted brown butter, then sprinkle evenly with half of the sugar-cinnamon mixture. Use a pizza cutter or sharp knife to cut dough north to south in 6 even strips. Then cut the strips into 6 pieces the other direction, so you should have 36 rectangular pieces of dough.
12. Take half of the sliced apples and lay them over the dough pieces in any way you like. I laid them on every other piece. You may not use all the apple slices, so just eat those instead!
13. Carefully stack the squares on top of each other (if some of the filling falls off, just spoon and smooth it back on top as best as you can).
14. Line two 9-by-5-inch loaf pans with parchment paper, then spray them. Prop up loaf pan and carefully stack a few squares into pan at a time, Unprop loaf pan and cover with a clean kitchen towel while you prepare second loaf the same way with remaining butter, sugar-cinnamon mixture and sliced apples.
15. Cover both prepared loaves with a clean kitchen towel and let rise 30 to 45 minutes until doubled.
16. Preheat the oven to 350 degrees F and uncover risen loaves. Bake them for 25-30 minutes until tops of loaves are a deep golden brown (you want them to be well-baked on top so the center is baked through).
17. Transfer baked loaves to a cooling rack and let cool 30 minutes in loaf pans. Then, carefully lift loaves out of pans, using parchment paper as handles. Serve warm or room temperature (loaves taste best the day they are made, but they can be stored, covered with plastic wrap and foil, at room temperature up to 3 days).