Preheat oven to 350 degrees and prepare a 9x13 inch casserole dish with nonstick cooking spray and set aside.
Whisk together flour, salt, sugar, and baking powder. Once well-mixed use a wooden spoon to mix in milk, eggs, and melted butter until just combined then pour into your prepared casserole dish and set aside.
Whisk together all ingredients for cinnamon swirl and then spoon into the cake batter. Use a butter knife and make swirls throughout the entire cake. Bake for 30-35 minutes until cooked through.
Once cooked through remove from oven and top with cream cheese frosting. Slice in squares and serve.