Preheat oven to 375 degrees F.
Line muffin tin with paper liners.
Mix together topping ingredients, use a pastry blender to cut in butter or use your fingers.
Mix together eggs, sugar and oil. Beat until creamy.
Add in lemon zest, juice, vanilla, baking soda, flour and salt.
Add in Greek yogurt. Batter will be slightly lumpy.
Fill muffin tins 3/4 full.
Sprinkle top with crumb mixture and bake for 18-22 minutes or until a toothpick comes out clean.
Mix together glaze. Add enough juice to get a good drizzling consistency.
Cool 5 minutes and then drizzle with glaze.