Preheat oven to 350 degrees F. Slice butter into pieces then add to a 9x13 inch baking dish. Place the pan in the oven while it preheats, to allow the butter to melt. Once butter has melted, remove the pan from the oven.

Batter: In a large bowl mix together the flour, sugar, baking powder, and salt. Stir in milk and vanilla, just until combined - batter may be slightly lumpy.

Assemble: Pour the mixture evenly into the pan, over the melted butter and gently spread into an even layer (don’t stir). Sprinkle chopped pecans on top, then brown sugar evenly over everything. Slowly drizzle the boiling water evenly over the top. Do not stir. Sprinkle ground cinnamon on top.

Bake for 40-45 minutes, or until batter is nearly set in the middle. Cool for 10 minutes before serving. Serve immediately, while it’s warm, with a scoop of ice cream, if desired.