Preheat oven to 350 degrees F. Cut butter into four pieces, place in 9 x 13″ baking dish, and place pan in hot oven to melt.
Meanwhile, whisk together flour, sugars, baking powder, and salt. Whisk in milk and vanilla until smooth. Carefully remove pan with melted butter from oven and place on stovetop. Pour flour mixture over the hot butter, and leave out on the stove while you do the next step.
In the same bowl, whisk together pumpkin, evaporated milk, remaining 1/2 cup sugar, egg, cinnamon, ginger, cloves, and salt. Pour pumpkin mixture evenly over flour mixture. You don’t need to stir it in, but do pour it all around the pan and not in just one spot.
Arrange the pear slices over the cobbler mixture, and sprinkle with cinnamon sugar if desired. Carefully (remember it’s hot!) return pan to the oven, and bake approximately 75 minutes or until top is golden brown. A toothpick inserted in the center should come out mostly clean when done.
Serve warm or cool on countertop and store in refrigerator until ready to serve.