In the bowl of a food processor, combine cream cheese and butter until smooth.

Add the sugar and flour to the processor bowl. Pulse 6-10 times until dough just comes together.

Divide dough into 3 disc shaped pieces. Wrap in plastic wrap and refrigerate for several hours or overnight.

In a small bowl, mix together the jam and the mandarin zest.

When ready to bake, heat oven to 350° F. Line baking sheets with parchment paper.

Use a rolling pin to roll out one piece of dough (leaving the others in the fridge until needed) between two sheets of parchment paper, into a circle about 12” in diameter and ⅛" thick. If the dough is sticky, sprinkle with additional flour as needed.

Gently place a 2" round cookie cutter or glass at the center of the dough circle to keep that area free from filling. Spread 2-3 tablespoons of jam filling over the dough, stopping ½" away from the edge and leaving a 2" circle at the center. Remove the round cookie cutter.

Use a pizza cutter or sharp knife to cut the dough into 16 equal wedges. For the most equal pieces, cut the dough circle into fourths, then cut each fourth into four wedges. Roll up each wedge from the outer edge to form little crescents.

Place on the prepared baking sheets 1"-2" apart, with the pointed end of the dough tucked under. In a small bowl, beat together the egg and water glaze, then brush over the cookies. Freeze the filled cookie sheet for 15 minutes.

While cookies are chilling, grind raspberries into a powder using a spice grinder or mortar and pestle.

Bake for 20-25 minutes until golden brown. Remove from oven.

Sprinkle immediately with sparkling sugar and freeze dried raspberry powder. Transfer onto wire racks to cool.

Store rugelach cookies at room temperature in air-tight containers, in layers separated by wax paper, for up to 5 days.