Banana Upside-Down Cake

• Pre-heat the oven to 350°F.

To prepare the topping:

• In an oven-safe 10-inch skillet, over medium heat, melt butter.
• Add the brown sugar, lemon juice and salt; whisk until the brown sugar melts; 1 to 2 minutes.
• Let cook, whisking constantly, until the mixture starts to smell like caramel and darkens slightly; about 1 minute longer – don’t walk away or the mixture may burn; the mixture will clump and separate, but that is normal.
• Add bananas and nuts; gently tossing to coat with the caramel.
• Remove from heat and arrange fruit into an even layer on the bottom of the skillet; ignore sugar clumps; they will dissolve during baking.

To prepare the cake:

• In a large bowl, whisk together the melted butter, sugar, vanilla and lemon zest until thoroughly combined.
• Whisk in eggs, one at a time.
• Add sour cream and whisk until well mixed.
• Sprinkle baking powder, salt and baking soda into the batter, one ingredient at a time, while whisking vigorously after each addition.
• Using a rubber spatula, gently fold in flour until just incorporated; the mixture will be lumpy but that is normal; don’t over mix; scrape batter into the skillet over the fruit and spread evenly.
• Place in the pre-heated oven and bake until surface is deeply browned all over, with darker brown edges, and the fruit is lightly bubbling around the sides of the skillet; about 35 to 45 minutes, rotating halfway through; a toothpick inserted into cake will come out clean when cake is done.
• Remove the cake from the oven and immediately run a butter knife or offset spatula around the edge of the skillet.
• Let sit for 10 to 15 minutes, on a wire rack, to cool slightly.
• Carefully invert cake into serving platter.
• If some fruit or nuts stick to bottom of skillet, gently remove them using an offset spatula or knife and place them back onto cake.
• Let the cake cool until the fruit topping sets, at least 30 minutes to 1 hour, before serving.
• Cake is best served on the day it is baked.