Preheat oven to 325 degrees F and generously grease pan with butter. Make sure every corner of the pan is greased, so that the cake does not get stuck. In a large bowl, whisk together flour, baking powder, and spices. Set aside.
Add butter, salt, and sugar to a very large mixing bowl. Use a handheld or stand mixer to cream the ingredients together on high speed until fluffy and smooth, about 2-3 minutes. Add pumpkin puree and beat on high speed until fully combined with the butter and sugar, about 1-2 minutes. Add vanilla, then one egg, and beat on low speed until fully combined before adding in the remaining eggs one by one. Be careful not to over-mix.
Now, add the dry ingredients, and beat on medium speed until just combined. Do not overmix, as this will cause the cake to be dry and dense. Once there are no longer any large streaks of flour remaining and the ingredients have formed a thick, cohesive batter, stop mixing. Use a spatula to give the batter one large stir to ensure that everything has been mixed together well. This batter will be thick and look like soft buttercream frosting.
Use a large spoon or ice cream scoop to add the batter to the prepared pan, filling the pan about three-quarters of the way. Be careful not to overfill. Bake in the preheated oven for about 55-60 minutes, or until a toothpick inserted in the center of the cake comes out clean. Remove from the oven and let cool in the pan for at least 10 minutes before inverting the cake onto a wire rack.
While the cake continues to cool, make the cream cheese glaze. In a medium bowl, beat cream cheese until smooth, then beat in powdered sugar until completely combined with the cream cheese. Lastly, stir in vanilla and milk. Once the cake is completely cooled, drizzle the glaze over the cake. Slice and serve.