With your Stand mixer bowl, with the flat beater, whisk together almond, butter, icing sugar and salt at low speed. Once homogenous, Add the eggs one by one. Don't worry if there are still lumps they will disappear once we add flour. Add the flour little by little. The dough should NOT be smooth it should still be clumpy. Remove from the bowl and finish smoothing it out by hand. The reason why we are doing this? We want to make sure that we don't overknead our dough. Lots of bakers have trouble with their pie dough retracting when they bake it. It's actually because gluten activate and becomes elastic. If you knead it too long (even with the flat beater!) when baking, the dough will retract. Cover your dough and let it rest for at least 2 hours in the fridge.