1. Mix butter and powdered sugar using a paddle attachment until well blended.
2. Add egg and mix until well combined. Add salt and vanilla.
3. Add flour in one step and on low-speed mix until just combined. Do not overmix.
4. Press dough evenly flat onto a sheet of plastic food film. Place dough in refrigerator or freezer for at least 30 minutes or until well chilled. Preheat oven to 375°F
5. Meanwhile chill work surface area that you will be rolling dough on by placing 1-2 cookie sheets filled with ice cubes on area. Set aside a 9-inch pie tin.
6. Sprinkle chilled area lightly with flour and roll dough into a circle large enough to cover entire pie tin. Place dough into place and remove excess. Press dough into any cracks or tears. Prick bottom and sides with a fork and place in oven. Place in oven and bake for about 13 minutes or until golden and edges are light brown.
7. Optional, but good to retain a crispy crust: brush interior of pie crust evenly with egg white and return to oven for 2-3 minutes. Remove from oven and set aside. Reset oven temperature to 325°F.
8. In a bowl large enough to hold all ingredients whisk eggs vigorously for 1 minute. Add sugar, honey, and whisk again vigorously. Add buttermilk, vanilla, salt, and whisk to combine.
9. Pour mixture into pie crust.
10. Place in oven and bake until pie is set and no longer “trembles” in center when pie is tapped, about 45 minutes. Let pie cool.
11. For topping, in a saucepan combine brown sugar, honey, cream, and butter. Bring to a boil and simmer for 3-4 minutes.
12. Remove from heat and stir in vanilla, salt, pecans, and cinnamon.
13. Spread onto pie.