1/2 cup plus 2 tablespoons grated Parmesan cheese, divided
Dissolve yeast in warm cream. In a large bowl, combine egg, sweet potato puree, sugar, salt, nutmeg, yeast mixture and 2 cups flour; beat on medium speed until smooth. Stir in enough remaining flour to form a soft dough (dough will be sticky).
Turn onto a lightly floured surface; knead until smooth and elastic, about 6-8 minutes. Place in a greased bowl, turning once to grease the top. Cover and let rise in a warm place until doubled, about 1 hour.
Punch down dough. Turn onto a lightly floured surface; roll into a 18×9-in. rectangle. Spread pesto to within 1 in. of edges; sprinkle with 1/2 cup Parmesan. Roll up jelly-roll style, starting with a long side; pinch seam and ends to seal.
Using a sharp knife, cut roll lengthwise in half; carefully turn each half cut side up. Loosely twist strips around each other, keeping cut surfaces facing up. Shape into a coil; place on parchment paper. Transfer to a 6-qt. slow cooker; sprinkle with remaining 2 tablespoons Parmesan. Let rise until doubled, about 1 hour.
Cook, covered, on low until bread is lightly browned, 3 to 3-1/2. Remove from slow cooker and cool slightly before slicing.