Preheat the oven to 350 degrees F. Add graham crackers, brown sugar, cinnamon, and a pinch of salt to a food processor. Blend until fine crumbs form, then add butter and continue to blend until the texture resembles wet sand.

Add the graham cracker crumbs to a springform pan. Press the crumbs against the sides and the bottom of the pan, really pressing into the pan to ensure that crust is packed and sturdy. Bake the pie crust for 12 minutes. Remove from the oven and set aside.

In a large bowl, add the egg yolks and use an electric mixer to beat the yolks for three full minutes - until the yolks are bubbly and pale in color. Then add the sweetened condensed milk and sour cream, mix until just combined, about 10-20 seconds. While continuing to mix, slowly pour in the lime juice and vanilla extract. Mix until just combined, about 30 seconds.

Pour the key lime filling into the graham cracker crust. Bake for 15 minutes, then remove from the oven and cool on the counter for 30 minutes, then place into the refrigerator for at least 3 hours.

To make the whipped cream topping, add cold heavy cream, confectioners' sugar, and vanilla extract to a large bowl and use an electric hand mixer and on medium high until stiff peaks form, then add on top of the pie.

Run a butter knife between the crust and the sides of the pan to loosen the crust and ensure that it doesn't stick to the pan. Top with fresh lime zest, mint, and lime wedges for garnish.