Preparation: Preheat your oven to a cozy 350°F (175°C). While it's heating, grease a 9×13-inch baking dish. Brace yourself—flavor euphoria awaits.

Batter Up: Into your mixer's bowl—be it stand or hand-held—sift the flour, then add the sugar, salt, and baking powder. Pour in the milk, crack in the eggs, and drip-drop the vanilla. Mix until just blended. No need to overmix; a little ruggedness adds character. Now, fold in the melted butter. Transfer this silky batter into your prepped baking dish.

The Swirl: Ah, the heart of the cake! In a separate bowl, beat together the room-temperature butter, brown sugar, and cinnamon. Considering nuts? Toss them in now. Drop this aromatic concoction in dollops onto the batter. Grab a knife and execute some artisanal swirls, blending the cinnamon mixture into the cake. Trust your instincts; you're an artist.

Into the Furnace: Pop the dish into your preheated oven. At 25 minutes, start checking its soul with a toothpick. If it emerges almost clean, it's time. Give or take, you're looking at a 25–30 minute bake.

The Glaze: Meanwhile, take a medium bowl and whisk together the confectioners' sugar, milk, and vanilla. Aim for a flowing but not watery consistency.

The Grand Finale: Once the cake is out of the oven and still warm—oh, that heavenly aroma—drizzle the glaze over it. Allow it to pool in all the nooks and crannies.