Preheat the oven to 350° and grease a 9x13 inch metal baking pan.

In the bowl of a stand mixer combine the vegetable oil, both brown and granulated sugars, and vanilla. Mix on medium speed until combined, about 30 seconds. Add the buttermilk, both eggs and pumpkin puree and mix on medium until the whole mixture comes together, about 1 minute. Make sure your buttermilk and eggs are room temperature so the batter doesn't clump!

In a separate medium sized bowl sift the flour, corn starch, cinnamon, pumpkin pie spice, baking soda, baking powder and salt. With the mixer on a low speed, gradually add the dry ingredients until smooth, about 1 minute.

Pour the batter into the prepared baking pan and bake for 35-45 minutes or until baked through. Remove from the oven and allow to cool completely before frosting.

Add the sugar to a sauté pan over medium-high heat. The sugar will look normal for the first few minutes, whisk occasionally. It will start to clump and melt, turning a deep amber color. Stir continuously until all of the sugar is dissolved. Once melted, stir in butter, one tablespoon at a time. After the butter melts completely, slowly drizzle in room temperature heavy cream, about 2 until completely combined. The mixture will bubble and steam up each time you add the heavy cream so be careful! Remove the caramel from heat and stir in the salt. Allow to cool to room temperature before using. Store for up to 2 weeks in the refrigerator.

Once the cake has cooled, make the frosting. In the bowl of the stand mixer beat the cream cheese on medium high until smooth, about 30-60 seconds. Add in the butter and again beat until smooth, about 1 minute. Add in vanilla, powdered sugar, salt and milk. Add in additional milk, 1 tablespoon at a time, until it reaches the desired consistency.

Once the cake has completely cooled, spread an even layer on the cream cheese frosting on top. Drizzle on about ½ cup of caramel (more in you prefer) and use a knife or spoon to swirl the caramel on top. Serve and enjoy! This cake should be stored in the refrigerator and will stay good for up to 5 days.