In a medium mixing bowo whisk together the flour, baking powder, and salt. Set aside.
In a stand mixer fitted with the paddle attachment, or a hand mixer in a large bowl, beat the butter until it is smooth. Add the sugar and beat until light and fluffy.
Scrape down the bowl, then add the egg, vanilla extract, and almond extract. Beat on low speed, then increase the speed to medium and beat until light and fluffy, about 3 minutes.
Turn off the mixer and add half of the flour. Mix on low speed just until incorporated, then continue to mix on medium speed until no flour remains. Add the rest of the flour and beat until combined, scraping down the bowl as needed.
Turn the dough out onto the counter. Bring the dough into a flat disc, divide evenly in half, and wrap each half in plastic. Refrigerate the wrapped dough discs for 30 minutes.
Take one disc from the refrigerator and leave the other one in. Between two sheets of parchment paper, roll out the dough evenly to 1/8-inch thick. You may need to tape the parchment in place before rolling, or place a silicone baking mat underneath the parchment to help anchor it. Leave the rolled dough in the parchment and refrigerate for 15 minutes.
Line two baking sheets with parchment paper and keep them near your workstation. Arrange an oven rack to the middle position and preheat the oven to 350°F.
Peel back the top sheet of parchment on the chilled rolled dough and set aside to use on the next round, or discard it if needed. Use a 2.5-inch heart cutter to cut as many hearts as possible from the dough. Use a 1-inch heart cutter to cut little hearts out of the center of half of the hearts. These will be the tops of the cookies. Transfer the hearts to a prepared baking sheet. Gather the scraps of dough into a disc, wrap, and refrigerate.
Bake the cookies for 6 to 7 minutes, until they are pale golden brown.
Transfer the cookies to a wire rack and cool completely. In a small bowl, stir to combine the raspberry jam, rose water, and lemon juice. Spoon about 1/2 teaspoon jam on each of the whole heart cookies. Spread the jam slightly, keeping most of it mounded in the center of the heart.
Dust the hearts with the cut out in the middle of them lightly with confectioners' sugar, then place them on top of the jam-topped bottom hearts.
Repeat with the rest of the refrigerated dough, rolling, chilling, cutting out, baking, and assembling. Always chill any scrap dough before working with it.