Make dough:  Add flour, 2-1/2 tablespoons of sugar, and salt in a large bowl. Whisk to combine.

Add cold butter cubes. Cut butter into the flour with a pastry blender or by using two forks to mash butter into the dry ingredients.  The mixture should be crumbly with very small pieces of butter sprinkled all throughout the flour. 

Pour in cold water and stir until the dough begins to come together. 

Sprinkle your work surface with a little flour and turn out the dough onto the floured surface. Work it into a ball and then flatten into a round disc. Wrap the disc in a piece of plastic wrap and place in the refrigerator to rest for at least 30 minutes.

In the meantime, in the same bowl you used for the dough, toss the pears with 3 tablespoons of sugar, vanilla, cinnamon, and cardamom. Place in the refrigerator while the dough rests. 

Preheat the oven to 400° F.

Place a sheet of parchment paper on your work surface. Unwrap the disc of dough and place it on top of the parchment paper. Using a rolling pin, roll the dough into a circle, anywhere between 10 and 12 inches in diameter. 

Add the pear filling to the center of the rolled out galette, leaving a 3-inch border of dough around the filling to allow for proper overlapping of the filling to create a beautiful rustic crust. Fold the dough over the pears, working in a circle, overlapping slightly as needed, and lightly pressing to seal dough any cracks. This does not need to be perfect. 

Brush the galette crust with egg wash mixture and sprinkle with turbinado sugar. 

Bake the galette until the crust is deep golden-brown, approximately 35-40 minutes. Allow to cool for 5-10 minutes. When ready to serve, sprinkle with a light dusting of powdered sugar. The galette will taste best if served warm on the day it is made. Enjoy!