Preheat your oven to 350°F (177°C) and line a 9×9-inch baking dish with parchment paper.

In a large mixing bowl, combine melted butter and brown sugar. Whisk until smooth and glossy, about 1-2 minutes. Add eggs, molasses, and vanilla extract, mixing until fully integrated.

In a separate bowl, whisk together flour, ground ginger, cinnamon, baking powder, and kosher salt until fluffy.

Gradually add the dry ingredients to the wet ingredients, folding gently until just combined.

Pour the batter into the prepared baking dish and spread evenly.

Bake for 30-35 minutes, checking for doneness with a toothpick.

Cool in the baking dish for about 15 minutes, then lift out using parchment and cool completely on a wire rack. Dust with confectioners' sugar before serving.