For the pumpkin cookies: Preheat oven to 350° F. In a large bowl, beat butter with an electric mixer on medium to high speed for 30 seconds. Add sugar, baking powder, baking soda, salt, cinnamon, and nutmeg. Beat until combined, scraping bowl occasionally. Add eggs and vanilla, and beat until combined. Beat in pumpkin. Beat in as much of the flour as you can with the mixer. Using a wooden spoon, stir in any remaining flour.

Drop dough by heaping teaspoons 2" apart on an ungreased cookie sheet. Bake for 10 to 12 minutes or until tops are set. Do not over bake. Transfer cookies to a wire rack and let cool.

For the frosting: In a small saucepan, heat butter and brown sugar until melted and smooth. Transfer melted butter to a medium bowl and stir in milk and vanilla. Beat in powdered sugar until smooth.

With a small spoon, place a dollop of frosting on a cookie, leaving a small indentation in the center of the frosting. Sprinkle lightly with cinnamon and then add some of the pecans and sea salt, pressing the pecans in ever so slightly to adhere. Frost two to three cookies at a time, so the toppings adhere to the frosting, until all cookies are finished. If desired, omit pecans and sea salt toppings.