1. Preheat the oven to 375°F and line 2 baking sheets with parchment paper, set aside.
2. In a large mixing bowl whisk together the flour, baking powder, salt, cinnamon, pumpkin pie spice and nutmeg. Set aside.
3. In the bowl of a stand mixer fitted with the paddle attachment beat the butter and brown sugar on medium speed until pale and fluffy, about 3 minutes. Mix in the eggs. Reduce the speed to low and add the pumpkin, evaporated milk and vanilla; mix well about 2 minutes (Batter will be loose). Add the flour mixture; mix until combined.
4. Use a small cookie scoop to place 1 1/2 tablespoon full mounds of the batter onto the prepared cookie sheets, spacing 1 1/2 inches apart. Bake the cookies, rotating the pans halfway through, until the tops spring back, about 12 minutes. Cool on the baking sheets for 3 minutes before transferring to wire racks to cool completely.

For the icing

1. Place the confectioner's sugar in a large mixing bowl. Melt the butter in a small saucepan over medium heat. Cook, swirling the pan occasionally until golden brown, about 3 minutes. Immediately, add the butter to the confectioner's sugar, scraping any browned bits from sides and bottom of pan. Add the evaporated milk and vanilla then stir until smooth.
2. Spread approximately 1 teaspoon of icing onto each cookie. If the icing becomes too stiff , stir in more evaporated milk a little at a time.
3. Lightly grate fresh nutmeg over the tops of the iced cookies and store in a single layer at room temperature. These cookies are best the day they are made, but can be stored at room temperature for up to 2 days