.Make the dough: In the bowl of a standing mixer fitted with a hook, combine yeast, 1/2 teaspoons of the sugar, and 1/4 cup water heated to 115°. Stir to combine and let sit until foamy, about 10 minutes. Add remaining sugar, milk, light brown sugar, vanilla, egg, and egg yolk. Beat on low speed until thoroughly combined, 1 minute. Turn mixer off and add the flour and salt. Mix on medium speed until the dough just comes together. Turn mixer speed to high and knead dough for 4 minutes. Add the butter and continue kneading until dough is smooth and pulls away from the side of the bowl, about 6 minutes. Remove bowl from the mixer, cover with plastic wrap, and set aside in a warm place. Let the dough rise for 1 1/2–2 hours, until it has doubled in size.
Meanwhile, make the filling: Combine the sugar, dark brown sugar, pecans, walnuts, raisins, cinnamon, salt, and cloves in a large bowl; stir to combine. Stir in the maple syrup. Set filling aside.
Punch the dough down and turn it out onto a heavily floured surface. Gently knead the dough until it's no longer sticky, adding more flour as necessary, about 1 minute. Using a floured rolling pin, roll the dough into a 10" x 10" square. In a small bowl, beat the cream cheese with a rubber spatula until it's smooth and spreadable. Spread the cream cheese evenly over the dough square; then fold square into thirds as you would fold a letter to fit it into an envelope. Take the open ends of the resulting rectangle and fold into thirds again, to make a smaller dough square. Invert the dough so that the seam is face down and, using the rolling pin, gently roll into a 10" x 20" rectangle.
Turn the dough so that the short sides are parallel to you. Brush the top of the dough with half of the melted butter. Drizzle the reserved filling over the dough, leaving a 1" border at the edge farthest away from you. Lightly press the filling into the dough. Using your hands, lift up the bottom edge of the dough and roll it forward into a tight cylinder. Place dough cylinder, seam side down, on a cutting board and, using a thin, sharp knife, trim off the ends; cut cylinder crosswise into 8 equal-size slices. Nestle the slices, cut sides up and evenly spaced from one another, into a buttered 9" x 13" light-colored metal baking pan. Cover pan with plastic wrap and set aside in a warm place to let rise for 2 hours. (Alternatively, the rolls may be refrigerated overnight.).
Heat oven to 375°F Uncover the rolls. (If refrigerated, let them sit at room temperature for 15 minutes.) Bake until golden brown and a toothpick inserted in the center of the rolls comes out clean, about 30 minutes.
Make the icing: While the rolls are baking, whisk together the sugar and buttermilk in a small bowl until smooth.
Transfer the pan of cinnamon rolls to a cooling rack; brush with remaining melted butter. Let cool for 5 minutes. Dip the tines of a fork into the icing and drizzle all over the rolls. Serve immediately.