Trim bases from fennel bulbs; cut into eighths, reserving fronds for another use. Arrange fennel in a lightly greased 11- x 7-inch baking dish.
Whisk together whipping cream and next 3 ingredients, and pour over fennel slices. Sprinkle fennel slices with breadcrumbs and Parmesan cheese; dot with butter.
Bake, covered, at 425° for 20 minutes. Uncover and bake 20 more minutes or until fennel is tender and yields when a knife is inserted into the thickest slices. Serve immediately.