Classic Italian Almond Butter Cookies

Preheat the oven to 350 degrees F (175 degrees C).
In a medium bowl, combine cake flour, all-purpose flour, baking powder, and salt.
In a large bowl, cream together butter, granulated sugar, and shortening with an electric mixer on medium speed until light and fluffy.
Mix in almond paste until thoroughly combined.
Add eggs, vanilla extract, lemon juice, and almond extract.
Reduce the mixing speed to low and slowly add the dry ingredients.
Scrape down the bowl once all dry ingredients are added, then mix on medium speed until evenly combined, about 30 seconds.
Fit a large pastry bag with an 864 or 4S tip and fill the bag with batter.
Pipe evenly sized cookies onto an ungreased cookie sheet, spacing them 1 1/2 to 2 inches apart, allowing cookies room to puff slightly during baking.
Bake in the preheated oven, in batches if necessary, until the bottom edges are slightly browned, 8 to 10 minutes.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.