Combine water, sugar, and yeast in a large bowl; let stand 5 minutes. Lightly spoon flour into dry measuring cups; level with a knife. Add 1 cup flour and butter to yeast mixture; stir just until combined. Cover and let rise in a warm place, free from drafts, 30 minutes.
Add pumpkin, salt, and nutmeg to flour mixture; stir until well combined. Add 2 1/4 cups flour; stir until a soft dough forms. Turn dough out onto a floured surface. Knead until smooth and elastic (about 8 minutes); add enough of remaining 1/4 cup flour, 1 tablespoon at a time, to prevent dough from sticking to hands (dough will feel tacky).
Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place, free from drafts, 1 hour or until doubled in size. Punch dough down; cover and let rest 5 minutes. Divide dough in half; place dough on a baking sheet or 8 inch cake pans, lined with parchment. Drizzle 1 teaspoon of olive oil over each round. Rub the oil over the tops and use your fingers to spread the dough out to fit the cake pans or to an 8 inch circle. Sprinkle cheese (don’t try to cut Camembert, just pull pieces off the rind) and nuts evenly over dough circles; press lightly to adhere. Lightly coat dough circles with cooking spray; cover and let rise 20 minutes (dough will not double in size).
Preheat oven to 400F.
Uncover dough; bake at 400F for 30 minutes or until loaves are browned on the bottom and cheese melts (shield loaves with foil to prevent overbrowning, if necessary). Cool on a wire rack