Mix the flour and salt in a large bowl. Add the cold butter cubes and use your fingers or a pastry cutter to work until the mixture resembles coarse crumbs with pea-sized pieces of butter remaining.
Gradually add ice water, one tablespoon at a time, mixing gently with a fork just until the dough begins to come together. Avoid overworking to keep the crust flaky.
Gather the dough into a ball, flatten into a disk, wrap in plastic wrap, and chill in the fridge for at least 30 minutes to relax the gluten and firm up the fat.
Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper. Retrieve the chilled dough, and on a lightly floured surface, roll it into a 12-inch circle.
Transfer the rolled dough onto the prepared baking sheet. Spread the cranberries evenly in the center, leaving about 2 inches of border around the edges.
Arrange apple slices over the cranberry layer, overlapping slightly and sprinkling vanilla extract over the top for added flavor.
Fold the edges of the dough over the filling, pleating gently as you go to create a rustic border, leaving the center exposed.
Brush the crust with the beaten egg for a glossy finish and sprinkle evenly with sugar for a sweet crunch.
Drizzle honey over the fruit filling, and scatter a few cranberries and apple slices on top for a beautiful presentation.
Bake in the preheated oven for about 40 minutes, or until the crust is golden brown and the fruit filling is bubbling and slightly thickened.
Remove the galette from the oven, let it cool for a few minutes, then slice and serve warm or at room temperature, enjoying the crisp crust and juicy fruit filling.