Preheat your oven to 425°F (220°C). Line a baking sheet with parchment paper. This will help give your galette that lovely golden crust without sticking to the pan.

In a medium-sized bowl, combine your sliced apples, light brown sugar, all-purpose flour, ground cinnamon, lemon juice, and vanilla extract. Toss everything together gently until the apples are evenly coated. Set this mixture aside for a few moments to let the flavors meld together.

On a lightly floured surface, roll the thawed puff pastry into a circle about fifteen inches in diameter. Don’t stress too much about making it perfect; the rustic look is part of the charm.

Carefully transfer the rolled pastry onto your prepared baking sheet. Ensure it’s centered and fully laid out.

Spoon the apple mixture directly into the center of the pastry, leaving about a 2-inch border along the edges. Ensure you pile of apples comes high; they will cook down and might look less impressive if you don’t add enough.

Now, gently fold the edges of the pastry over the filling. You want to create a crimped edge while leaving the center exposed. This is where all that deliciousness is happening!

Take your beaten egg and brush it over the folded pastry edges. This will give it that nice golden color once it’s baked. If you're feeling a bit extra, sprinkle the edge with coarse sugar for added texture and crunch.

Scatter a few tiny pieces of butter over the filling. This will add richness as it bakes, making the apples even more luscious.

Pop it in the oven and bake for about 20-25 minutes or until the crust is a beautiful golden brown and the apples are bubbling.

Once baked, remove it from the oven and let it cool for a few minutes. Serve warm, ideally a la mode with vanilla ice cream or with whipped cream. Trust me, the combination is heavenly!