Move the top rack into the top 1/3 of the oven. Preheat the oven to 325 degrees F. Line a large baking sheet with parchment paper.
In a bowl, combine the flour, baking powder, cinnamon, and salt.
In a large bowl, cream together the butter and sugar. Then, mix in the eggs, vanilla, orange zest, and orange juice.
Mix the dry ingredients into the wet ingredients, just until combined.
Using a rubber spatula, mix in the chopped cranberries.
Dump the dough out onto a lightly floured surface. Cut the dough into 2 equal pieces and roll each one out into logs about 10 inches long and 1 1/2 inches around.
Transfer the logs to the parchment-lined baking sheet. Gently press down the tops to create slightly flatter logs.
Bake the biscotti logs for 30 minutes. They should be lightly brown and a bit firm but still soft enough to slice.
Allow the logs to cool for 10 minutes before slicing to prevent crumbling. Cut across the logs to create 1/2 inch thick slices. Place the cookies cut side down on the parchment-lined baking sheet. Bake for 10 minutes, flip, and bake for another 10 minutes.
Turn the oven off but leave the cookies in the oven for up to 20 minutes to finish drying them out. Allow them to cool on a wire rack.
Store the cookies in an airtight container for up to 2 weeks.
Notes
Zest the orange before slicing it open for the juice.
Make sure to chop the cranberries. If they are left whole, it can create weak spots in the cookies that result in them breaking or crumbling.
I used 3/4 cup chopped cranberries for this recipe, which resulted in cookies with quite a bit of cranberry bits in them. You can reduce the amount to 1/2 cup if you want bigger areas of cookie without cranberries.