In a small skillet, caramelize the pecans in butter and brown sugar for 5-6 minutes until lightly browned. Cool and set aside.
In a medium saucepan, heat the half and half to under 200 degrees. Stir in the brown sugar until dissolved. Whisk a small amount of the hot cream mixture into the eggs and pour into pan, whisking constantly. Cook and stir over low heat until the mixture coats the back of a metal spoon.
Remove from the heat and place saucepan in a bowl of ice water. Stir in whipping cream and vanilla. Press plastic wrap onto the surface of the custard and refrigerate overnight.
Churn/Freeze according to the manufacturer’s directions. Allow ice cream to firm up in freezer for several hours before serving.