Either with a hand mixer in a large bowl, or in the bowl of a stand mixer fitted with a paddle attachment, cream the sugar, vegan butter, salt, and optional citrus zest until light and fluffy. Add the plant-based yogurt and vanilla extract, mixing until thoroughly combined.

Add the all-purpose flour and almond meal. Mix on low speed until just combined (switching to a rubber spatula if mixing by hand), ensuring not to overmix.

Transfer the dough to a sheet of parchment paper and place another sheet on top. Roll the dough to a thickness of ⅛-inch (about 3 mm) using a rolling pin. Place the rolled dough, still sandwiched between the parchment sheets, on a baking sheet and refrigerate for 20 minutes until firm.

Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper. Using Linzer cookie cutters, fluted round cookie cutters, or the rim of a small glass, cut out the cookies. Make half plain and half with a heart (or other shape) cut-out in the center. Arrange the cookies on the prepared baking sheets. Place the baking sheet in the freezer for 3-5 minutes to firm the dough again.

Bake for 8-10 minutes, keeping a close eye to ensure the edges do not brown. Let the cookies cool completely on a wire rack.

Dust the cookies with the heart cut-outs lightly with powdered sugar. Spread the jam evenly onto the flat side of the plain cookies. Sandwich the cookies together with the powdered sugar-dusted heart cookies on top.

Store the finished cookies in an airtight container in the refrigerator for up to 1 week. If the powdered sugar dissolves, re-dust the stored cookies again before serving.