Preheat your oven to 350°F (175°C). Grease and flour your 9-inch round cake pans. In a large bowl, whisk together the flour, baking powder, baking soda, salt, and cinnamon.
In another bowl, combine the vegetable oil, applesauce, brown sugar, granulated sugar, and eggs. Add the first teaspoon of vanilla extract and mix until well combined.
Gradually add the dry ingredients to the wet mixture, stirring until just combined. Fold in the shredded carrots and chopped pecans if using.
Divide the batter evenly between the two prepared cake pans. Bake for 25-30 minutes or until a toothpick inserted into the center comes out clean. Allow the cakes to cool completely in the pans before transferring them to a wire rack.
In a mixing bowl, beat the cream cheese until smooth. Add the sweetened condensed milk and the remaining vanilla extract, mixing until well combined. In another bowl, whip the cold heavy cream until stiff peaks form. Gently fold the whipped cream into the cream cheese mixture until fully incorporated.
Once the cakes are cool, place one layer on a serving plate. Spread a generous layer of the cream cheese ice cream over the first cake layer. Place the second cake layer on top, pressing gently. Freeze the assembled cake for at least 4 hours or until firm.
Once the cake is firm, whip the remaining 2 cups of heavy cream with powdered sugar until soft peaks form. Spread the whipped cream over the top and sides of the cake. Garnish with chopped pecans if desired.
Slice into your Carrot Cake Ice Cream Cake and enjoy the delightful layers of flavors and textures!