Place a 10-inch cast iron skillet into the oven and preheat to 450-degrees.
In a bowl, combine the sugar and lemon zest. Toss 2 TBSP lemon sugar with the strawberries. Set aside.
In a blender, combine eggs, milk, flour, salt, and vanilla, and blend 30 seconds on high speed until smooth, scraping down the sides of the blender halfway through to make sure all flour is incorporated.
Add butter to the hot skillet and place back in the oven.
When the butter has melted, carefully pour dutch baby batter into the skillet. Sprinkle with ½ cup strawberries and the remaining lemon sugar. Place in the oven and bake for 15 minutes, until golden and puffy.
Serve with additional strawberries. Enjoy!
Notes
Make Ahead: You can make the batter up to two days ahead of time and refrigerate until ready to bake. Give the batter quick whisk to combine just before baking, then bake as directed below.