Preheat your oven to 180°C / 350°F / 160°C fan and line your cake tin with grease-proof paper or grease well.
Add your oil, milk, syrup, vanilla, lemon juice and zest to a bowl and whisk to combine. Set aside.
In a large mixing bowl - add your sifted flour, ground almonds, baking powder, baking soda, and salt and mix until combined.
Pour in your wet ingredients and mix until almost combined.
Gently fold in the blueberries.
Transfer the batter to your cake tin and smooth out the top. Sprinkle the crumble on top, making sure to cover the whole top of the cake.
Bake for 25-30 minutes - insert a skewer to check the doneness - it should come out with just a few moist crumbs.
Leave to cool for around 10 minutes, then remove from the cake tin and leave on a wired rack to cool completely before slicing!
Serve with custard, cream or enjoy as is!