In the bowl of a stand mixer fitted with the paddle attachment, beat butter and sugar at medium speed until light and creamy, 2 to 3 minutes, stopping to scrape sides of bowl. Beat in egg until combined. Beat in extracts.

In a medium bowl, whisk together flours and salt. With mixer on low speed, gradually add flour mixture to butter mixture, beating until just combined. Use immediately, or cover and refrigerate until ready to use. Refrigerate in an airtight container for up to 1 week.