Step 1

In a medium bowl combine together the 1 cup butter, brown sugar, flour and cinnamon until well blended. Transfer to a piping bag fitted with a round tip (I use a 1/2 inch/1 1/2 cm diameter) or a zipper lock bag snipped in one corner. Set aside.

Step 2

Spray or butter and flour an 11-inch round pan (preferably springform).

Step 3

In a medium bowl, whisk together the flour, granulated sugar, baking powder and salt. Set aside.

Step 4

In a large liquid measuring cup or small bowl, whisk together the milk, eggs and vanilla.

Step 5

Pour the milk mixture into the flour mixture and whisk just until combined. Lumps will remain.

Step 6

Slowly drizzle in the melted butter to the batter while mixing. The batter should now be smooth but a few lumps are OK.

Step 7

Pour the cake batter into the prepared pan, then starting in the center pipe the "Goo" in a circular motion going around and around towards the sides of the pan until the goo is all finished.

Step 8

Bake for 30-35 minutes or until a toothpick inserted in the center of the cake comes out clean. Do not insert the toothpick in the 'Goo" area, because that is supposed to be gooey anyway.

Step 9

Remove the removal rim of the pan, if using the springform pan, and transfer to a serving platter. Or leave it in the pan if using a regular one (without a removable rim).

Step 10

Drizzle the glaze all over the cake, then leave it to cool for about 10 minutes before serving.

Step 11

This cake tastes best when served warm out of the oven when the "Goo" is still melty, but cooled portions of the cake can be warmed in the microwave.

Step 12

Store leftovers in a airtight container.

Step 13

In a small bowl, whisk together the powdered sugar, milk and vanilla until smooth.