Preheat oven to 350° and line a baking sheet with parchment paper.
In a large microwave safe bowl add the softened cream cheese, cut into chunks. Microwave for 30 seconds to make a little softer. Stir in the shredded gruyere, salt and pepper.
In a large frying pan, melt 3 tbsp butter over medium heat. Once melted, add the onions and stir. Let cook until softened stirring occasionally, about 6-8 minutes. Once softened and slightly translucent, add the 1/3 cup white wine. Let cook another 3-5 minutes, until a deep amber color. Remove from heat.
On a floured surface, roll out one tube of crescent roll dough. Pinch together seams so it stays in one piece. Using a 9" or 10" plate or pie dish, use a knife to cut around, making a circle out of the dough. Carefully lift and transfer to the parchment lined baking sheet. Spread 1/3 of the cheese mixture on top and then spread 1/3 of the caramelized onions on top of that. Roll out the second crescent roll tube in the same way, floured surface, cut into circle, place on top of the first layer. Layer 1/3 of the cheese mixture and 1/3 of the onions. Then roll out the third tube, lay on top of the second layer. Spread the last bit of cheese mixture and layer the last of the onions. Finally, roll out the last tube of crescent roll dough and transfer on top of the third layer.
Place a small cup or bowl, 2"-3", in the center of the circle. Take a sharp knife and cut into 16 wedges. First make 4 cuts in a + shape (leaving the small cup/bowl so not cutting through the entire thing), then cut those in half, then cut those pieces in half again. That will be 16 pieces. Take 2 pieces next to each other and turn away from each other, twist 3 times then pinch together at the bottom to seal it. Continue until finished.
In a small bowl, whisk the egg and 1 tbsp water. Brush the top of the snowflake with the egg wash and bake for 25-30 minutes until golden brown on top. Let rest 5 minutes before serving. Enjoy!