• Preheat oven to 400°F.
• Grease muffin cups or line with cupcake papers.
• Take about 2 Tbsp of the flour and toss with the blueberries in a separate bowl.
• In a bowl, mix flour, sugar, sea salt, and baking powder.
• And in a large bowl, mix up the starter, melted butter, eggs, lemon extract, and buttermilk.
• Mix the dry ingredients, a little at a time, beating well after each addition.
• The batter should be stiff. If it's hard to stir, add a Tbsp more of buttermilk.
• Now gently fold in the blueberries.
• Divide the mixture between 12 muffin cups for great zonking big muffins, or 18 to 24 for more normal sized ones.

Topping

• The butter should be really cold. Cut it into cubes.
• In a small mixing bowl combine the flour, sugar, and lemon zest.
• With a pastry blender or 2 forks, cut the butter into the flour mixture until it's well combined. It should look like crumbs.
• Divide the topping between the muffins.
• Press it down a little bit. Gently.
• Now put those guys into the oven and bake for 20 to 25 minutes.
• Check to see if they're done with a toothpick. If you poke the toothpick in the top and it comes out clean the muffins are done.
• Take them out of the oven and turn them out onto a cooling rack to cook.