Place rack in the middle of the oven and heat to 350F.
Line a baking sheet with parchment paper or a reusable liner.
Combine flour, sugar, pumpkin pie spice, baking powder and salt in a large bowl. Set aside.
Using an electric mixer or handheld mixer, whisk eggs, pumpkin puree and vanilla together.
Whisk the melted butter into the wet ingredients slowly so that the mixture does not get too warm.
Pour the liquid mixture into the dry ingredients and stir/knead until a dough forms.
Transfer dough to a floured surface to shape into two flat logs that are about 2-inches wide and 1/2-inch tall.
Sprinkle coarse sugar on top pressing it slightly into the logs so that it adheres.
Bake logs until they are firm to the touch, about 50 minutes.
Let cool completely.
Heat oven to 300F.
Cut logs into 1/2-inch wide slices and place the slices cut side down in a lined baking sheet.
Bake for an additional 40 to 50 minutes turning the cookies over halfway through, they should be dry and have no cakey bits.
Let cool on a wire rack and store in an airtight container.
These cookies are AMAZING dunked into coffee, tea or milk!
You can make these biscotti over two days, letting the logs cool overnight.
The logs are much easier to cut once they have cooled.