Preheat your oven to 400°F and prepare a baking sheet with parchment paper.
Take your cooled dough out of the refrigerator. Form the dough into a circle.
Lightly flour your work surface and roll your dough out with a rolling pin to ⅛ inch thick, about 12 inches. Fix any cracks by pinching them along the way.
Carefully transfer the dough by wrapping it around your rolling pin onto your prepared baking sheet.
Create a 10-inch circle by sprinkling the almond powder in the center of your galette dough. You will have a 2-inch border of plain dough.
Once again, toss to coat the raspberries in the bowl before use. Top the almond powder with the raspberry filling also leaving a 2-inch border of dough.
Take the border dough and fold it over the raspberries to create the galette crust. Use the parchment to help fold it over.
If the dough has gotten too warm at this point you can pop it back in the refrigerator for 15 minutes. You want it nice and cold when it goes into the oven for this step will help the dough keep its shape.
Using a pastry brush, brush the edges of the crust with beaten egg to promote browning. Then sprinkle the edges with sanding sugar (optional).
Bake the galette for 40-45 minutes or until the crust is golden brown. Turn the galette at the halfway mark. Keep a watchful eye on the crust so it doesn’t get too brown.
For the glaze, put the raspberries, sugar, dried hibiscus flowers and a splash of water in a small saucepan and cook over low heat. Simmer until the raspberries have released their juices and the syrup is dark pink and fragrant from the hibiscus, about 5 minutes. The amount you have will depend on how juicy your raspberries are. It should be the consistency of syrup or warm jam. Strain into a bowl.
Brush all the glaze over the raspberries in your hot galette. Let it cool for 15 minutes and serve while still warm.