Preheat your oven to 350°F (175°C) and grease two round cake pans. In a large bowl, whisk together the flour, pumpkin pie spice, baking powder, baking soda, and salt.

In another bowl, cream together the softened butter and granulated sugar until light and fluffy. Add eggs one at a time into the creamed mixture while mixing well after each addition. Stir in vanilla extract, buttermilk, and pumpkin puree until combined.

Gradually add the dry mixture into the wet mixture. Mix until just combined; overmixing may lead to a denser cake texture.

Divide batter evenly between prepared pans and smooth out the tops. Bake in preheated oven for about 38 minutes or until a toothpick inserted into the center comes out clean.

Prepare your latte soak by combining espresso, whole milk, sweetened condensed milk, pumpkin pie spice, and vanilla extract in a bowl.

Carefully remove cakes from pans onto wire racks. Poke holes across each layer and generously drizzle latte soak over both layers while they are still warm. Let them cool completely before frosting.

Beat softened butter and cold cream cheese together until creamy. Gradually add powdered sugar while mixing on low speed until smooth; then mix in vanilla extract, instant espresso powder, and pumpkin pie spice until fully incorporated.