Preheat oven to 425F (220C) and line muffin tin with paper liners. Set aside.
In a medium-sized bowl, whisk together flour, sugar, baking powder, salt. Set aside.
In a separate, large bowl, whisk together canola oil, buttermilk, lemon juice, and lemon zest.
Add eggs and vanilla extract and whisk until well incorporated.
Add dry ingredients into wet ingredients and use a spoon or spatula to gently stir ingredients together until mostly combined (a few dry lumps are OK, it is critical to the fluffiness of our muffins that you don't overmix).
Portion batter into prepared muffin tin, filling each liner over 3/4 - way to the top with batter (do not overflow. I like to use a standard ice cream scoop with a lever to easily portion my batter).Set aside while you prepare your crumble topping.
Whisk together flour and sugar.
Use a pastry cutter to cut in butter until mixture is combined and like coarse crumbs.
Sprinkle tops generously and evenly with crumble topping and place muffin tin in preheated oven.
Bake on 425F (220C) for 8 minutes and then reduce the oven temperature to 350 (175C) (do not open the oven door or remove the muffins, just leave them in and reduce the temperature) and bake another 12 minutes.
Remove muffins and allow to cool while you prepare lemon glaze.
Lemon Glaze (optional)
While the muffins cool, prepare your glaze by whisking together powdered sugar, lemon juice, and water
Drizzle glaze over the top of each cooled muffin. Allow to sit and harden about 10 minutes before serving.
Lemon Muffins https://sugarspunrun.com/lemon-muffins/ Find more great recipes at SugarSpunRun.com!