Preheat the oven to 350 degrees Fahrenheit.
Grease and line an 8x8 square pan with parchment paper and set aside.
In a large mixing bowl, whisk together all wet ingredients.
Add in the dry ingredients, making sure to spoon and level the flour, don't scoop from the bag.
Whisk until you get a smooth batter, it will be quite thick.
Transfer to your prepared pan and smooth out the top.
Bake for 48-55 minutes or until a toothpick comes out clean.
Let cool in the pan for 10-15 minutes, then flip onto a wire rack to finish cooling.
Meanwhile, prep the frosting.
Add the softened butter and cream cheese to a bowl and beat together for about 2 minutes.
Beat in the powdered sugar, followed by the vanilla, cinnamon and salt. If it is too thin, add more sugar, if it's too thick, add a few teaspoons of soy milk.
When the cake has cooled completely, frost and slice into 12 squares and enjoy!
You can also omit the frosting for a slightly lighter and healthier version and serve with some whipped cream and cinnamon.