For the Cake

1. Preheat the oven to 350°F and set an oven rack in the middle position. Grease a 9-x-13-inch baking dish with butter or nonstick cooking spray.
2. In a medium bowl, whisk together the flour, baking soda, baking powder, salt, cloves, cinnamon, and nutmeg; set aside.
3. In a large bowl of an electric mixer, beat the melted butter and sugar on medium speed until just combined. Add the eggs one at a time, beating well after each addition. Beat in the pumpkin. Add the dry ingredients and mix on low speed until well combined.
4. Turn the batter into the prepared pan and smooth the top. Bake for 40 to 45 minutes, or until a cake tester inserted into the center comes out clean. Set the cake on a wire rack to cool completely.

For the Frosting

1. In a large bowl of an electric mixer, beat the butter and cream cheese together on high speed until smooth and creamy, about 1 minute. Beat in the salt and vanilla. Add the confectioners' sugar and beat on low speed for 30 seconds, then switch to high speed and beat until light and creamy, about 2 minutes. Spread the frosting on the cooled cake. Cut into squares and serve. Cover any leftover cake tightly with aluminum foil and store in the fridge for up to 4 days (bring to room temperature before serving) or at room temperature for up to 2 days.
2. Make-Ahead Instructions: The cake can be made and frosted up to two days ahead of time. Cover tightly with aluminum foil and store in the refrigerator; allow the cake to come to room temperature before serving.
3. Freezer-Friendly Instructions: Freeze the unfrosted cake, tightly wrapped, for up to 3 months. When ready to serve, defrost the cake to room temperature, make the frosting, frost, and serve.