Take a pan dry roast the almonds and keep aside.
In the same pan on slow flame cook jaggery with water as you keep stirring it.
Gradually jaggery will dissolve well in water and it would start cooking and thickening at this moment add butter and mix well.
Jaggery would turn into thick sauce and to test you drop the jaggery on a clean surface and it would crystallise.
Add vanilla and mix well and then with a spoon dip almonds one by one so the jaggery sauce gets coated nicely and evenly and them keep it on a plate with butter paper.
Each almond should be kept separately so they don't stick to each other and jaggery would crystallise in 2-3 mins. Alternatively you can keep in fridge too before you enjoy the caramelised sticky jaggery toffee over the crunchy almonds