Melt butter in a large skillet over medium-high heat. Add onion, celery, and garlic; cook for 3-4 minutes, or until translucent. Transfer onion mixture to a large bowl; stir in hazelnuts, pecans, almonds, rosemary, thyme, sage, and crushed crackers.
In another medium bowl, combine broth and eggs. Add broth mixture to stuffing mixture; stir well and let sit 1 minute for moisture to absorb.
Transfer mixture to an 8-x8-inch baking pan; cover with foil. Bake at 350° for 30 minutes; remove foil and bake an additional 10-15 minutes or until golden.
To Serve in a Pumpkin:
1 medium pumpkin, seeds removed and insides cleaned
Preheat oven to 400°.
Place pumpkin, without lid, in a baking pan with 1-inch of water. Cover with foil. Bake at 400° for 30 minutes or until softened. Pour off any remaining water.
Reduce heat to 350°. Fill pumpkin with stuffing mixture. Cover with foil; bake in a baking pan for 30 minutes. Remove foil and bake an additional 10-15 minutes, or until top is golden and internal temperature reaches 165°. Serve immediately.