Pre-heat oven to 350°F.
Line a rimmed baking sheet with a non-stick baking mat or parchment paper; to catch overflow during baking.
In a large bowl, toss the peaches with the lemon juice.
In a separate bowl, whisk together the flour, baking powder and baking soda.
In a 10-inch cast-iron skillet, over medium heat, cook 1/4 cup of the granulated sugar, stirring occasionally with a wooden spoon, until the sugar melts and turns a deep amber color; about 10 minutes.
Remove from the heat and immediately add 2 tablespoons of butter, stirring vigorously; the mixture may appear curdled and broken; don’t worry, it will smooth out.
Arrange the peach wedges in concentric circles over the sugar mixture, overlapping as needed to make them fit.
In a stand mixer, fitted with the paddle attachment, beat the remaining sugar, butter and vanilla extract, on medium speed, until smooth.
Add the eggs, one at a time, beating until blended after each addition.
Add the sour cream and beat until blended.
With the mixer running on low speed, gradually add the flour mixture; beating just until blended; stop ocassionally to scrape the bowl as needed.
Spoon the batter over the peaches in the skillet and spread to cover.
Place the skillet on the prepared baking sheet.
Place in the pre-heated oven; bake until golden brown and a tester inserted into the center of the cake comes out clean; 40 to 45 minutes.
