Preheat oven to 350°; coat the inside of a 9x5 inch loaf pan with nonstick cooking spray and dust it with flour.
In a bowl, combine the flour, baking soda, baking powder, cinnamon, salt, cloves, and nutmeg ; set aside.
In a large mixing bowl, combine the butter and sugar; cream with an electric mixer on med-high speed until fluffy, about 3 minutes, scrape down the sides of bowl as needed.
With the mixer on med-low speed, add the eggs, one at a time, scraping down the sides of bowl after each addition; stir in the pumpkin and vanilla; stir in the milk.
Turn the mixer to low speed and add the flour mixture 1/2 cup at a time, scraping down the sides of the bowl after each addition.
Stir in the chocolate chips and walnuts.
Scrape batter into prepared pan and smooth the top with a rubber spatula.
Bake for 55 minutes - 1hour, until the cake is firm to the touch and a pick comes out clean.
Let the cake cool in the pan for 5 minutes, invert it onto a wire rack, and then turn it right side up on a rack to cool completely.
Store uneaten cake in a cake keeper at room temperature for up to 3 days or in the refrigerator, wrapped in plastic, for up to 1 week.