Add peeled and diced potatoes to a pot and cover with water. Bring to a boil, reduce heat, and allow to simmer for 20-25 minutes until potatoes are tender. Drain your potatoes and then return them to the pot.
Return pot with potatoes to the stove on low heat. Add 5 tbsp of butter and cream cheese to the pot and start mashing.
Once creamy slowly add half and half and milk. Add just a little at a time until you get the consistency that you want.
Keep mashing then add seasoning salt and pepper. Stir and place in a casserole dish.
Add remaining 3 tbsp of butter to the top and bake at 350 degrees for 10-15 minutes or until butter is melted and potatoes are warm.