Easy Apple Crumble with Vanilla Custard Sauce

Apples - 500gm (about 2-3 medium-sized apples)

Wheat flour / atta -

Salted butter - 100gm + a bit for greasing

Sugar - 2tbsp + 2 tbsp

Salt -

Lemon juice - a few drops (optional)

Cinnamom stick - 1 (optional)