Mix squash, olive oil, salt, cayenne, and brown sugar and place in roasting pan. Place in oven and roast until pieces are tender. About 30 minutes.
While squash is cooking, prep onions by placing 1 tablespoon butter in medium hot skillet and cooking until browned. This took me about 20 minutes. Remove onions from pan, wipe out any moisture and place remaining tablespoon butter in pan. Cook until it starts to bubble, then add fresh sage and fry until sage becomes darker and butter is browned. Remove sage from pan and set aside on paper towel.
If using crescent rolls: Unroll dough into 1 large rectangle on work surface. Press into 12x9-inch rectangle, firmly pressing perforations to seal. If using dough sheet: Unroll dough on work surface. Press into 12x9-inch rectangle.
Cut dough into 6 squares. Gently press squares into 6 ungreased muffin cups, shaping edges to form rims 1/4 inch high.
Mix cooked squash (will still be hot) with 3 pieces of sage (crumble the sage into the squash), and havarti cheese. Scoop squash into muffin cups. Top with caramelized onions.
Bake 15 to 20 minutes or until edges are golden brown. Cool 5 minutes. Remove from muffin cups and garnish with fried sage leaf.