Place cream in large bowl; let stand out at room temperature for 1 hour. Add vinegar; stir until thickened. Stir in yeast until dissolved; add the egg yolks. In a small bowl, combine flour and salt. Cut in butter. Gradually add to creamed mixture and mix well. Divide dough in half; wrap in plastic wrap. Cover and refrigerate overnight.
In a small saucepan, combine the pecans, 1/4 cup sugar, brown sugar and milk. Cook and stir over medium heat for 3 minutes; set aside.
On a floured surface, roll each portion of dough into a 12-in. x 10-in. rectangle. With a sharp knife or pastry wheel, cut dough into 2-in. squares. Place 3 in. apart on lightly greased baking sheets.
Cut through the dough from each corner of the square to within 1/2 in. of the center. Spoon 1/2 teaspoon of filling into the center of each square. Fold alternating points of the square to the center to form a pinwheel. Press a cherry half into the center of each. Sprinkle with remaining sugar.
Bake at 350° for 10-12 minutes or until edges begin to brown. Remove to wire racks. Store in an airtight container. Yield: 5 dozen.