1️⃣ Preheat the oven to 350°F (175°C). Grease a 9×13-inch baking pan to prevent sticking.

2️⃣ Prepare the bottom layer: In a large bowl, mix together 3 cups of flour, milk, white sugar, eggs, baking powder, vanilla extract, and salt until smooth. Add the melted butter and stir until well combined. Pour the batter evenly into the prepared baking pan.

3️⃣ Prepare the cinnamon topping: In a separate bowl, beat together the softened butter, brown sugar, 2 tablespoons of flour, and cinnamon until smooth and creamy.

4️⃣ Create the swirl: Drop spoonfuls of the cinnamon mixture over the batter in the pan. Use a knife to swirl it into the batter, creating a marbled effect throughout the cake.

5️⃣ Bake: Place the pan in the preheated oven and bake for 25-30 minutes, or until a toothpick inserted into the center comes out with only a few moist crumbs. Avoid overbaking for a soft, cake-like texture.

6️⃣ Make the glaze: While the cake is baking, prepare the glaze by mixing the confectioners’ sugar, milk, and vanilla extract in a bowl until smooth.

7️⃣ Glaze and serve: Once the cake is finished baking, drizzle the glaze over the warm cake for a sweet finish. Serve warm for the best flavor and texture.