Directions

1. Preheat oven to 325 degrees. Line two baking sheets with parchment paper and set aside.
2. In a large bowl, whisk together flour, salt, and baking powder; set aside. In the bowl of an electric mixer fitted with the paddle attachment, cream together butter and sugar on medium-high speed until light and fluffy, about 2 minutes. Add eggs, one at a time, beating well after each addition. Add vanilla and lemon juice and beat until well combined.
3. With the mixer on low, add the flour mixture in two batches, mixing until just incorporated. Turn dough out onto a clean work surface. Divide in half, and pat into flattened rectangles; wrap each in plastic wrap. Refrigerate at least 2 hours or up to 1 week.
4. Working with one piece at a time, on a lightly floured work surface, roll out dough to a 1/8-inch thickness. Using a 5-inch heart-shaped cookie cutter, cut out hearts. Transfer to prepared baking sheets, about 2 inches apart. Refrigerate until firm, about 15 minutes. Repeat process with remaining rectangle of dough. Gather all the scraps, and roll out again. Chill 15 minutes; cut out more heart shapes, and place on baking sheets.
5. Bake, rotating baking sheets halfway through cooking, until cookies are golden around the edges and slightly firm to the touch, about 15 minutes. Transfer cookies to a wire rack to cool completely. Cookies may be stored in an airtight container for up to one week.