Unexpected Success (a.k.a. Raspberry Skillet Upside Down Cake)

Buying stuff for the kitchen is an obsession for me.  Obsession #2, right after food itself.  So, armed with new Le Creuset cast iron skillet (yes, it was my second, but this was a different SIZE... everyone who is anyone knows that size matters, so that resets all past purchases!!), I decided to try out a recipe that was a hybrid between Bi-Rite Market's "Skillet Upside Down Pear Cake" and this one.  Deadly, if I do say so myself. 


1/2 cup firmly packed light brown sugar
1/3 cup butter (about 3/4 stick butter) -- SAVE THE WRAPPER
1.25 cups fresh raspberries
1 cup all-purpose flour
1/2 tsp baking powder
Good pinch salt
3 large eggs
1.25 cups sugar
1 tsp vanilla essence

Preheat the oven to 350°.  Get a cake stand or flat plate (diameter larger than the skillet) ready.

Melt the butter in a pan of your choice (not the skillet you will be using).  Mix the brown sugar and melted butter in the skillet and spread it evenly over the bottom.  Now take the saved butter wrapper and rub it on the sides of the skillet... it will be sufficient grease.  If you think it's not enough, dip into the butter-sugar mixture a bit... it's sufficient, trust me.
Arrange the raspberries, over the brown sugar in the skillet, filling the entire space so no butter-sugar mixture is visible. 
Mix the flour, baking soda and salt together in a bowl.  In the bowl of an electric mixer, beat the eggs for about a minute at high speed, then add the sugar.  Beat the mixture until it is light and fluffy, about 5 minutes.  Add the vanilla extract and beat another 30 seconds or so.  Add the flour mixture and beat until everything is smooth and combined.  Do not overmix, or the cake will tend towards a tough crumb.
Pour the batter over the berries in the skillet, then carefully spread it out to cover the berries, and even out the surface, if needed.  Bake the cake until the top is firm and golden, about 35 – 40 minutes.  Check the cake with a toothpick or tester; it’s done when it comes out clean-ish (a few sticky crumbs never hurt anyone).
Carefully remove the skillet from the oven and carefully invert the skillet onto your cake stand or plate.  Leave it to sit for a couple of minutes so that the skillet fully releases the fruit and butter-sugar mixture.  Remove the skillet, and voila... best enjoyed warm (and it stands up to a bit of warming up in the microwave, without any compromise in taste).