To make the dough. In the bowl of a stand mixer fitted with the dough hook, combine the milk, yeast, and honey. Let sit 5-10 minutes, until bubbly on top. Add 3 ½ cups flour, the cardamom, salt, eggs, melted butter, and 1 tablespoon lemon zest. Using the dough hook, mix until the flour is completely incorporated, about 4-5 minutes. If the dough seems sticky, add the remaining ½ cup of flour.Cover the bowl and let sit at room temperature for 1 hour or until the dough has doubled in size.To make the filling. In a small bowl, combine the sugar and the remaining 1-2 tablespoons lemon zest. Line a 9x13 inch baking dish with parchment. Lightly dust your work surface with flour. Turn out the dough, punch it down, and roll it into a rectangle about 10 x 16 inches. Spread 6 tablespoons softened butter evenly over the dough. Sprinkle the lemon sugar evenly over the butter and lightly push into the butter. Starting with the long edge closest to you, carefully roll the dough into a log, keeping it fairly tight as you go. When you reach the edge, pinch along the edge to seal. Using a sharp knife, cut the log into 12-16 rolls. Place the rolls in the prepared baking dish. Cover and let rise 20-30 minutes or transfer to the fridge to rise overnight (see notes).Preheat the oven to 375° F. Bake the rolls for 20 to 25 minutes, or until golden brown.Meanwhile, make the icing. Beat together the cream cheese, butter, powdered sugar, and vanilla until light and creamy.Spread the icing over the warm rolls. Serve warm and enjoy!