In a 12" castiron pan, begin to melt butter over medium-high heat. Allow it to bubble and foam, and after about 5 minutes, check with a spoon to see check that it's becoming golden brown. Cook until there are brown specks in the butter, but it is not burned. Transfer to a bowl and reserve browned butter. Using a baking brush, brush leftover butter in the pan along the bottom and sides of the pan.

Preheat oven to 425 F. In a large bowl, combine all the dry ingredients. In a medium bowl, whisk together the eggs, milk, and brown butter. Add wet ingredients to the large bowl with flour and dry ingredients and stir until combined. Scoop into the pan and level out with a spatula. Sprinkle with dried rosemary and rosemary salt, and bake for 20 minutes. Let cool for 10 minutes, slice and serve warm.