Preheat oven to 350° and line muffin tins with paper liners.
In a medium bowl, mix together the 2 flours and salt. Set aside.
Using an electric mixer, cream the butter until light and fluffy. Gradually add sugar while continuing to beat. Add eggs one at a time, scraping down the sides of the bowl if necessary.
With mixer on low speed, add half-and-half and vanilla extract. Once added, increase speed to combine well.
Add flour mixture and beat just until flour is incorporated. Stir in white chocolate and nuts. Evenly divide batter between 12 muffin cups and bake for approximately 25 minutes.