For the Cake:
1. Preheat your oven to 350°F (175°C). Lightly grease and flour a 9×13 inch baking dish, or line it with parchment paper.
2. In a large bowl, whisk together the gluten-free flour blend, baking soda, baking powder, cinnamon, nutmeg, ground ginger, and salt. Ensure everything is well combined.
3. In a separate bowl, combine the pumpkin puree, brown sugar, eggs, vegetable oil (or melted coconut oil), milk, and vanilla extract. Mix until smooth.
4. Gradually add the wet mixture to the dry ingredients. Mix on low speed until just combined. Do not overmix the batter.
5. Pour the batter evenly into your prepared dish. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.
6. Let the cake cool in the pan for 10-15 minutes. Then, transfer it to a wire rack to cool completely before frosting.

For the Cream Cheese Frosting:
1. In a medium bowl, beat the softened cream cheese and softened unsalted butter together with an electric mixer on medium speed until smooth and fluffy (about 2-3 minutes).
2. Gradually add the confectioners’ sweetener, one cup at a time, mixing well after each addition.
3. Stir in the vanilla extract.
4. Beat the frosting until it is light and airy. If the frosting seems too thick, add 1-2 tablespoons of milk, one tablespoon at a time, until desired consistency is reached. If it is too thin, add more confectioners’ sweetener.
5. Once the cake is completely cool, spread the cream cheese frosting evenly over the top.