Mixing the Dough - In a large bowl, combine the flour, active dry yeast, sugar, and salt. Add the softened butter and egg yolks and mix everything with an electric mixer equipped with the dough hook attachment, on low speed, until a smooth and elastic dough forms, for about 5-10 minutes. - Make sure the butter is at room temperature and cut into chunks, so it can mix easily with the flour. You can also mix the dough by hand on a floured surface, kneading it for about 10-12 minutes, until the dough is soft and tacky.

Preparing the Filling - Roll out the marzipan on a floured surface into a 10 x 5 inches rectangle. Peel and grate the apples and mix them with the raisins. Distribute the apple-raisin mixture over the marzipan, leaving some space around the edges. Roll up the marzipan tightly, enclosing the filling and sealing the edges. Place it in the fridge to chill for 15-20 minutes. - Use a piece of plastic wrap to help you roll the marzipan tight and avoid it from sticking to the surface. If the marzipan is too soft, you can dust it with some confectioners' sugar or skip the rolling and shape it with your hands. You can also add some cinnamon or cardamom to the apple-raisin mixture for more flavor.

Shaping and Baking the Kringle - Preheat the oven to 375°F (190°C). Divide the dough into two equal portions. Roll out each dough portion into a 10 x 15 inches rectangle on a floured parchment paper. Place the marzipan roll in the middle of each dough rectangle and fold the edges over the marzipan, pinching and sealing them together to create a boat-like shape. Brush the dough with milk using a pastry brush. Bake the kringles for 25-30 minutes, until golden and puffy. Remove them from the oven and transfer them to a wire rack to cool. Slice and serve at room temperature. - Use a sharp knife or a pizza cutter to slice the dough edges into strips and create the dough boat shape. You can also brush the dough with egg wash or melted butter instead of milk for a richer color and flavor. Don't worry if the dough cracks or breaks, you can always patch it up with some extra dough. Serve the kringle with a dollop of whipped cream or a sprinkle of powdered sugar, if desired.