Creating the Fluffy Lemon Meringue Pie can be straightforward if you follow these simple steps:

For the Pie Crust:

1. Preheat Oven: Preheat your oven to 425°F (220°C).
2. Mix Dry Ingredients: In a mixing bowl, combine flour and salt.
3. Cut in Butter: Add chilled butter to the flour mixture. Use a pastry cutter or fork to blend until the mixture resembles coarse crumbs.
4. Add Water: Stir in cold water, one tablespoon at a time, until the dough comes together.
5. Roll Out Dough: On a floured surface, roll out the dough to fit a 9-inch pie plate.
6. Fit into Pie Plate: Place the rolled-out dough into the pie plate and trim the edges. Poke holes in the bottom with a fork to prevent bubbling.
7. Bake: Bake the crust in the preheated oven for about 10-12 minutes or until lightly golden. Remove from oven and let cool.

For the Lemon Filling:

8. Combine Dry Ingredients: In a saucepan, mix together the sugar, flour, cornstarch, and salt.
9. Add Water: Gradually stir in water and cook over medium heat, stirring constantly until the mixture comes to a boil.
10. Thicken Mixture: Once boiling, continue cooking for 2 minutes until thickened.
11. Temper Egg Yolks: In a separate bowl, whisk the egg yolks. Slowly add a small amount of the hot mixture to the yolks to temper them. Then, gradually whisk the tempered yolks back into the saucepan.
12. Add Lemon: Stir in the lemon juice, lemon zest, and butter. Cook for an additional 2 minutes, stirring constantly until thickened.
13. Pour Filling: Pour the lemon filling into the pre-baked pie crust, smoothing the top.

For the Meringue:

14. Beat Egg Whites: In a clean mixing bowl, beat the egg whites and cream of tartar until soft peaks form.
15. Add Sugar: Gradually add sugar, continuing to beat until stiff peaks form and the mixture is glossy. Add vanilla and mix briefly.
16. Spread Meringue: Spoon the meringue over the lemon filling, spreading to the edges to seal.
17. Bake: Bake in the oven for about 10-12 minutes, or until the meringue is golden brown.

Cooling and Serving:

18. Cool: Remove from the oven and let the pie cool at room temperature for at least 30 minutes before slicing.
19. Chill: For best flavor, refrigerate the pie for a couple of hours before serving.