Yes you can, the texture will be a little more nubbly and not quite as soft and fluffy. But it still produces a good cake. Plus homemade almond meal does provide a more pronounced almond flavour. For the swap you just need to substitute the same amount of almond flour used in the recipe for raw whole almonds, with skin is fine. It’s a 1:1 substitution. I recommend grinding your almonds in a food processor with a couple of tablespoons of the amount of caster sugar used in the recipe. This will create a finer grind without the worry that you’ll start making almond butter.