PLACE a 12″ cast iron skillet in center of oven. PREHEAT oven to 450°F, and LET skillet preheat.
COMBINE cranberries, 3 large strips of orange zest, cardamom, maple syrup, ¾ tsp. salt and ⅓ cup water in a medium saucepan. HEAT over medium heat and COOK, stirring often and reducing heat as needed, until cranberries have burst and sauce is thickened, about 5 -10 minutes. TRANSFER to a medium bowl and LET cool.
Vigorously WHISK eggs, milk, sugar, vanilla, ½ tsp. finely grated orange zest and remaining ¾ tsp. salt in a large bowl until smooth, about 1 minute. Gently WHISK in flour until no large lumps remain.
Carefully ADD 2 Tbsp. butter to PREHEATED skillet, TILTING to coat bottom and sides. POUR batter into skillet and immediately TRANSFER to oven. BAKE until pancake is puffed and golden brown around the edges and the center is set but still custardy, about 10–12 minutes.
SPOON cranberry compote over pancake. TOP with more butter and maple syrup. CUT into wedges to SERVE.