Pulse pistachios in a food processor until reduced to powder (some small chunks are ok, but not to paste). Scrape into a bowl with 2 T. white sugar.
Drizzle with 3 T. melted butter; stir with a fork until mixture starts to clump. Pulse cranberries in food processor until finely chopped. Stir into pistachio.
Put 1 cup butter, powdered sugar, vanilla, baking powder, salt and remaining 1/2 cup white sugar in a bowl. Cream together with a mixer until well mixed. Mix in egg. Add flour; mix on low until incorporated.
Scrape dough onto a large, generously floured sheet of parchment paper. Dust top of dough with more flour, then press into a rough square. Roll into a 12x15 rectangle. Sprinkle pistachio-cranberry mixture evenly over dough, leaving a 1/2 inch border of uncovered dough. Brush top border with water.
Tightly roll dough starting on the long edge, using the parchment paper to help lift dough, ending with the wet edge and press lightly to seal. Slide dough and parchment onto a baking sheet; cover with plastic wrap. Freeze 1 hour, or chill 4-8 hours. (You can chill up to 3 days or freeze up to 3 months before slicing and baking.)
Preheat oven to 350 F. Line baking sheet with parchment paper. Slice chilled roll into 1/2 inch thick cookies; set on sheet. Bake for 13-15 minutes, or until edges are starting to turn golden brown. Transfer to a wire rack to cool.