In a small saucepan, combine the maple syrup and rosemary; allow to gently warm over low heat until fragrant.

Place a 10-inch cast-iron skillet on the center oven rack and preheat the oven to 425°F.

While the oven is preheating, combine the milk, flour, eggs, sugar, vanilla, and salt in the container of a blender. Blend on high for 20 seconds, scrape down the sides of the container, and blend again for a few more seconds. Let the batter rest until the oven is hot. (This helps hydrate the flour for a fluffier, tender pancake.)

Once preheated, blend the batter for a few seconds, then carefully remove the hot skillet from the oven. Add the butter to the skillet and swirl until melted. Immediately pour the batter into the skillet.

Bake for 20 minutes or until the pancake is very puffed and deep golden brown around the edges. (It will shrink as it cools.) Dust with confectioners sugar.

Immediately top with arugula, brie cheese, prosciutto, eggs and rosemary maple syrup. Serve hot!