Brownie Thins

Position rack in lowest third of oven; preheat to 350°F. Butter 2 baking sheets.

Place butter and chocolate in medium microwave-safe bowl. Microwave on medium-high power until almost completely melted, about 1 minute.

Whisk until smooth.

Add sugar and egg; whisk until smooth, about 1 minute.

Add flour, both extracts, and salt; stir just to blend.

Let batter stand 10 minutes.

Scoop rounded teaspoonfuls batter onto prepared baking sheets, spacing apart (12 per sheet). Spray sheet of plastic wrap lightly with nonstick spray.

Place, sprayed side down, over cookies. Using fingers, press each mound into 21/2- to 2 3/4-inch round.

Remove plastic wrap.

Sprinkle pistachios over rounds.

Bake cookies, 1 sheet at a time, until slightly darker at edges and firm in center, about 7 minutes. Cool on sheet 2 minutes.

Transfer cookies to rack; cool completely. DO AHEAD: Can be made 5 days ahead. Store airtight at room temperature.