Combine gluten free multi-purpose flour, granulated sugar, baking powder, and kosher salt in a food processor and pulse until mixed.

Add cold unsalted butter and cream cheese, blending until mixture resembles coarse sand.

Transfer the mixture to a mixing bowl.

Add cold milk and vanilla extract, pulsing until dough starts to come together.

Gently shape the dough into a rectangle about 1 inch thick, wrap in plastic wrap, and refrigerate for 10-15 minutes.

Roll out the dough to about ¼ inch thick and fold it in a tri-fold manner before chilling again for 15 minutes.

Chop dark chocolate and combine with cocoa powder, light brown sugar, and a pinch of salt in a bowl.

Roll out the chilled dough again, brush with melted butter, sprinkle with chocolate filling, and roll into a log.

Slice the log into 1-inch wide pieces, place on a baking sheet, and refrigerate for an hour.

Preheat oven to 400°F and bake rugelach for about 10 minutes before lowering to 350°F and baking until golden brown for an additional 15-20 minutes.