Preheat oven to 350F. Lightly grease a 9-in tart pan with a removable bottom. Set aside.
In the bowl of a stand mixer OR with a handheld electric mixer, beat butter and sugars together until completely creamy, about 1-2 minutes. Beat in peanut butter, egg, and vanilla until smooth.
Add baking soda, salt, and flour to liquid mixture and beat until a soft dough forms. Pat dough into the bottom and up the sides of prepared tart pan. Chill crust in freezer 20 minutes.
Bake crust at 350F 15-20 minutes or until crust is a light golden brown. (crust will puff up as it bakes-- use the bottom of a drinking glass to flatten back down once removed from oven) Cool on a wire cooling rack.
Chocolate Ganache
Place chocolate in a large bowl and set aside. In a small saucepan, heat cream until it reaches a low simmer. Remove from heat and pour over chocolate. Whisk ganache until chocolate is completely melted and smooth. Whisk in vanilla.
Pour chocolate ganache into cooled crust. Chill tart at least 2 hours until ganache is firm. Top tart with candied peanuts and slice into wedges. Enjoy!