Combine water, yeast and 1 teaspoon sugar in a small bowl. Let stand for 5 minutes, until foamy. Heat buttermilk and butter until warm (100° to 110°F); butter will not be completely melted. Add milk mixture to large mixer bowl with 1/4 cup sugar, salt, eggs, 2 cups flour and yeast mixture. Beat for 2 minutes on medium speed. Add enough remaining flour to form a soft dough.
Turn out onto lightly floured surface and knead 6 to 8 minutes, until smooth and elastic. Place dough in a greased bowl, turning once to coat. Cover and let rise in a warm, draft-free place until doubled, about 1 hour.
Combine brown sugar, cinnamon and cloves in a small bowl and mix well.
Punch dough down. Roll dough into a 16 x 12-inch rectangle. Spread butter over the dough, leaving 1/2-inch border around all sides. Sprinkle with brown sugar mixture. Roll up from long side and cut into 12 equal slices. Place in a greased 13 x 9-inch pan.
Cover and let rise in warm draft-free area until doubled, about 30 minutes.
Bake in preheated 350°F oven for 20 to 25 minutes or until golden brown. Cool 5 minutes and then invert on wire rack. Cool rolls for at least 30 minutes.
Split each roll in half horizontally and lay out on counter in pairs. Beat cream, 1/4 cup powdered sugar and 2 tablespoons coffee flavored liqueur in a large bowl with electric mixer until stiff peaks form. Set cream aside. In a second bowl, beat mascarpone, 1/2 cup powdered sugar and 2 tablespoons coffee flavored liqueur until creamy. Fold in 1/2 cup of the whipped cream.
Combine coffee and remaining 1 tablespoon coffee flavored liqueur. Drizzle over cut sides of tops and bottoms of rolls. Spread bottom portion of each roll with the Mascarpone Filling and replace roll tops. Dollop whipped cream mixture on top of each roll. Place cocoa powder in a small sieve and dust over tops of rolls. Garnish with chocolate curls, if desired. Serve immediately; refrigerate any leftover rolls.