Combine shallot and clam juice in a 10" skillet; bring to a boil over medium-high heat. Add cream. Cook for 3 minutes or until liquid is almost evaporated. Stir in vanilla bean paste.
Reduce heat to low, and whisk in butter, 1 Tbsp. at a time, whisking after each addition, until butter melts. Swirl pan, as necessary after each addition of butter, removing pan from heat to prevent butter from browning. Whisk in vodka and salt. Serve hot.