Preheat a 6-quart oval slow cooker to high. Coat the bottom and around 3-inches up side of the crock pot with melted butter.
In a large mixing bowl use a whisk to sift together the corn meal, flour, sugar and salt.
In a separate medium-size mixing bowl whisk together the buttermilk, eggs and oil. Stir in the cream style corn by hand.
Using a large spoon or spatula mix the wet ingredients into the dry ingredients until fully combined.
Pour the batter evenly into the slow cooker. Place doubled paper towels over the opening then secure the lid on top. (To prevent condensation from dripping back into the cornbread.)
Cook on high for 2 hours. Uncover and test the center checking for moist crumbs.