Preheat your oven to 350 degrees Fahrenheit.
Add the sugar, flour, baking powder, salt and lemon zest to a large bowl. Mix these ingredients together using a wire whisk until everything is combined.
Add the raspberries and gently toss them in the flour mixture until they're well coated and dispersed throughout the flour mixture.
Add the oil, Greek yogurt, eggs, and lemon juice to a separate bowl and combine them well with a fork. Once they're combined, dump the mixture into the bowl with the dry ingredients.
Using a rubber spatula, gently combine the wet and dry ingredients just until the flour disappears. Be careful not to over-mix and be sure to be gentle with the mixture so as not to break up the raspberries more than necessary.
Line 18 muffin cups with paper liners and divide the muffin batter evenly between the 18 liners. The batter will seem thick - this is normal!
In a small bowl, combine the 1/4 white sugar and the 1 tbsp lemon zest. Stir these together with a fork until the zest is mixed evenly throughout the sugar.
Sprinkle a tiny bit of this mixture evenly over the top of each of the 18 muffins before baking.
Bake the muffins at 350 degrees Fahrenheit for about 25 minutes or until the tops have browned slightly and the muffins spring back when you press the top lightly with your finger.
It's a good idea to let the muffins cool completely on a wire rack before serving, if you can wait that long before digging into the raspberry lemonade goodness!