Combine flours: In a small bowl, whisk together all-purpose flour, almond flour, baking powder, and salt, then set aside.
Combine butter and sugar: In the bowl of a food processor, combine softened butter and granulated sugar, processing until smooth and creamy (about 30 seconds). Add the egg and vanilla extract, pulsing until just mixed.
Add flour mixture: Gradually add the flour mixture in three batches, processing until combined. The dough will be soft and slightly sticky.
Chill dough: Scrape the dough into a bowl, cover, and refrigerate for at least 30 minutes or up to an hour to firm up. You could also chill dough overnight.
Heat oven: Preheat your oven to 350°F and line two baking sheets with parchment paper.
Roll cookie balls: Using a 1-tablespoon cookie scoop, portion the dough and roll it into balls between your hands. Place cookie balls on prepared baking sheets about 2 inches apart. The more you make these cookies, the more you'll be able to eye it for the size and you won't need to measure them.
Make indentation: Once one baking sheet is filled, use your clean thumb and gently press an indentation into the center of each ball. Or use using a 1-teaspoon measure. If the dough cracks, simply roll it back into a ball and try again.
Fill with jam: Fill each indentation with the jam.
Finish rest of dough: Repeat with the remaining dough for the second baking sheet.
Bake: Bake the cookies for 15-20 minutes, or until lightly golden brown around the edges. The cookies will be soft, and firm up as they cool down. Start checking for doneness at around 12-13 minutes, every oven is different. Let them rest on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely. If you like, using a sieve, dust cookies with confectioners’ sugar. Enjoy!