Toast pecans in oven at 350 °F for 5 minutes. Then take out and let cool.
In a large mason jar combine vodka, split vanilla bean, and toasted pecans. Cover and store vodka mix in a cool dark place for 3 weeks. Mix up mason jar often.
After two weeks remove pecans and vanilla pods in a strainer. Store in cool dark place for pecan extract.
To Make Liqueur
After pecans and vanilla have seeped in vodka and strained out then you can turn pecan extract into liqueur. Combine white sugar, brown sugar and water in a medium saucepan and heat over medium heat to a boil or until all the sugar as dissolved.
Take sugar mixture off heat and let cool completely. Add to mason jar and store in refrigerator to keep chilled for later.