Preheat oven to 350 degrees. Line 16 muffin cup holes with liners (reserve a few extra, in case you have extra cheesecake. I got 16.) Place one Pecan Sandie cookie in each cup.
Beat room temperature cream cheese with a hand mixer until fluffy. Beat in room temperature sour cream. Beat in egg, sugar, and vanilla until (mostly) no lumps remain. (Room temperature ingredients are a must to avoid lumps, believe me!) Stir in chopped pecans and toffee bits.
Evenly divide (about 2 tablespoons each) cheesecake among cookie crusts. Bake for 18-20 minutes, until they just begin to brown. Cool completely and refrigerate for at least 3 hours or overnight.
To make the topping, melt butter and brown sugar in a medium saucepan. Boil for about 2 minutes and remove from heat. Immediately stir in toasted chopped pecans. Place about 1/2 teaspoon on each cheesecake. Work fast - this hardens as the mixture cools. Let cool before serving.
To toast pecans, place in a small saucepan over low heat for just a few minutes. DO NOT WALK AWAY. They burn quickly!
Store in refrigerator.