Kick the tires and light the fires to 375 degrees.
Whisk together your dry ingredients.
Once those are mixed, add in the lemon zest.
Combine the yogurt, melted butter, lemon juice and egg. I whisked mine together rather rapidly to ensure a complete mix. Add to the dry ingredients and combine.
Grease the tins or line them with paper muffins cups and fill them 1/3 of the way, then place a blackberry on the batter. Fill the rest of the tin to 2/3 of the way. Roll 3 blackberries on sugar and place on top of the muffin. Sprinkle on extra lemon zest if desired.Repeat for all 12 muffins.
Bake at 375 for 14-17 minutes, until the tops spring back when touched. The lovely brown outside is thanks to the smidgen of butter in the recipe, toasting it up. This makes a perfect, beautiful dozen.