Preheat the oven to 375 degrees F.
Place the mashed sweet potatoes
, brown sugar, melted butter, salt, ground cinnamon
in the bowl of a stand mixer fitted with a paddle attachment. Mix at medium speed, about 1 minute. Add the evaporated milk
, sweetened condensed milk, bourbon, ginger
, vanilla extract, orange zest and eggs. Mix until smooth at low speed, 3 to 4 minutes. Pour the mixture into the chilled All Butter Pie Crust
Place the pie in the oven for 20 minutes, reduce the heat to 350 degrees F and bake until the crust is golden brown and the center of the pie has a slight wiggle when shaken, an additional 25 to 28 minutes. Remove the pie from the oven and place on a cooling rack
To make the maple syrup meringue
, bring the maple syrup to a boil in a small heavy bottomed saucepan
over medium heat. Clip an instant-read thermometer onto the pan.
Place the egg whites in the bowl of a stand mixer with a whip attachment. Once the syrup reaches 225 degrees F, start whipping the whites at medium-high speed. Slowly sprinkle the sugar into the whites and whip
until soft peaks, about 2 minutes.
When the syrup reaches 238 degrees F, lower the speed of the mixer
to medium and carefully add the maple syrup, pouring the syrup along the side of the bowl. Increase the speed to medium high and continue whipping, an additional 3 to 4 minutes. The meringue should be thick and shiny.
With a spatula
, spread the meringue over the entire pie, making sure to go all the way to the crust. Toast the meringue with a blow torch or place under the broiler until lightly brown, 1 to 2 minutes.
Serve chilled or at room temperature.