Preheat oven to 350 degrees. Line a rimmed baking sheet with a Silpat baking mat. In the bowl of an electric mixer, whisk egg white and sugar on medium speed until combined, about 30 seconds. Reduce speed to low; add flour and salt. Beat to combine. Beat in butter, cream, and extract, about 30 seconds.
Place a leaf stencil in corner of prepared baking sheet. Using a small offset spatula, spread batter in a thin layer over stencil. Carefully lift stencil. Repeat, filling baking sheet with leaves. Bake until tuiles are golden, 6 to 8 minutes. Using a small offset spatula, lift cookies, and quickly drape over a rolling pin to cool.
Repeat process until all batter is used. Store leaves in an airtight container at room temperature up to 2 days.