In a large bowl, stir together the flour, sugars, salt and cinnamon.
3 Cups Flour, 1 Cup Brown Sugar, 1/2 Cup White Sugar, 1 teaspoon Kosher Salt, 2 Tablespoons Cinnamon
Melt the butter and allow to cool just slightly so it's still melted but not hot.
1 Cup Unsalted Butter
Stir the butter into the dry ingredients and do not break up clumps unless they are huge. Set aside.
For the Cake
Heat the oven to 350 degrees and spray a 9x13" pan with nonstick spray and set aside.
In a standing mixer, beat the butter and sugar until fluffy, about 1-2 minutes. Add the oil and mix again.
1/2 Cup Unsalted Butter, 2 Cups Sugar, 1/2 Cup Vegetable Oil
Crack in your eggs and add the vanilla and then give the mixer a final turn before dumping in all dry ingredients. Mix until almost incorporated and then add in the buttermilk and stir until barely combined.