Preheat oven to 350 degrees F. In a small saucepan, combine the 1/3 cup brown sugar, the 2 tablespoons butter, and the 1 tablespoon water. Cook and stir over medium heat until mixture comes to boiling. Pour mixture into a 9x9x2-inch baking pan, spreading to cover bottom. Arrange pear slices in a decorative pattern on top of brown sugar mixture; set aside. In a medium bowl, stir together flour, baking powder, ginger, nutmeg, baking soda, salt, and cloves; set aside.
In a large bowl, beat the 1/2 cup butter with an electric mixer on medium to high speed for 30 seconds. Add the 1/3 cup brown sugar; beat until combined. Beat in eggs and molasses until combined.
Alternately add flour mixture and the 3/4 cup water to butter mixture, beating on low speed after each addition just until combined. Pour batter evenly over pear slices in pan, being careful not to disturb pear.
Bake for 35 to 40 minutes or until center springs back when lightly touched. Cool in pan on a wire rack for 5 minutes. Using a sharp knife or narrow metal spatula, loosen edges of cake from sides of baking pan. Carefully invert onto a serving platter. Serve warm. If desired, top each serving with sweetened whipped cream. Makes 9 servings.