1. Make the tuiles: Preheat oven to 350 degrees. Put butter and sugar in the bowl of an electric mixer fitted with the paddle attachment. Mix on medium-high speed until pale and fluffy, about 2 minutes. Mix in egg whites, extract, and vanilla seeds; reserve vanilla bean for another use. Reduce speed to low. Add flour and salt; mix until just combined.

2. Spoon 1 1/2 teaspoons batter onto a baking sheet lined with parchment paper; using an offset spatula, spread into a 4-inch round. Repeat, forming 3 more rounds and spacing 2 inches apart.

3. Bake until golden, about 10 minutes. Transfer sheet to a wire rack. Working quickly, remove 1 cookie with an offset spatula, and roll around the handle of a wooden spoon to form a 1/4-inch tube. Hold until tuile begins to harden, about 10 seconds; transfer tuile to a wire rack to cool completely. Repeat with remaining cookies. If cookies become too cool to shape, return to oven for 30 seconds. Repeat with remaining batter.

4. Make the cream: Process nuts in a food processor until they resemble coarse meal. Reserve 3 tablespoons; transfer remainder to a medium bowl. Add butter, sugar, cream, and salt; stir until smooth. Transfer to a pastry bag fitted with a 1/4-inch plain round tip (such as Ateco #10). Gently pipe filling into 1 end of a tuile, forcing it halfway in with a skewer; pipe into opposite end until filled. Dip each end in reserved nuts. Repeat with remaining tuiles. Serve immediately.