A rich take on an easy classic, the bourbon butter adds a layer of depth, elevating this rustic French pastry.
Whisk together the flour, sugar, and salt. Add the butter cubes, tossing them in the flour and working them in by pinching them into flat discs until they're the size of peas.
Make a well in the center, and add the water a few tablespoons at a time and mix just until the dough comes together, pulling flour into the well from the sides. Form the dough into a disc and refrigerate for at least 30 minutes.
Add all the ingredients to a small saucepan. Simmer all the ingredients together until aromatic and the butter turns a deep golden brown.
Preheat the oven to 375° F
On a floured surface, roll the dough into a 1/8" thick round disc with a diameter of about 10". Begin laying the apple slices in concentric circles until you reach the middle. Brush the bourbon butter generously on the apple slices.
Fold the edge of the dough over. Brush with the egg and sprinkle with the muscovado sugar. Bake for 40 minutes or until the galette is a deep golden brown.