Preheat the oven to 356°F (180°C). Pick your dandelions and remove the petals. The easiest way is to split each flower head in half and pinch the petals out, starting from the center.
Take the butter out ahead of time so it reaches room temperature. It should be soft enough to slice easily. Mix it with the brown sugar in a large bowl.
Beat until creamy and fluffy, about 2-3 minutes. A few visible sugar crystals are nothing to worry about. For a smoother mixture use powdered sugar.
Add the egg yolk, spelt flour, baking powder, salt and freshly grated orange zest to the bowl.
Stir until the mixture looks crumbly and dry. Keep mixing for two minutes. It will gradually turn buttery and start holding together on its own.
Briefly knead the dough in the bowl, then roll it into a ball. Cover tightly and rest at room temperature for 30 minutes. No refrigerating at this stage.
Divide the dough into two equal logs, roughly ¾ inch (2 cm) thick. Cut into ½ inch (1.5 cm) slices and roll each one into a ball. You can also portion them by tablespoon or weigh them at 18 grams each. The dough makes about 27 cookies.
Arrange the balls on a parchment-lined baking sheet with at least 1.5 inches (3-4 cm) between each one.
Using your thumb or a teaspoon, press an indentation into each ball. Refrigerate the tray for 10 minutes before baking.
Bake for 10 minutes until just lightly golden. Ovens vary, so start checking at the 8-minute mark.
Move the cookies to a cooling rack. For the filling, melt the apricot jam in a small saucepan with a teaspoon of orange zest. Once runny, stir in the dandelion petals and a small squeeze of lemon juice.
Once cooled, dust them powdered sugar if using.
Spoon the warm dandelion jam into each cookie. Work carefully if the cookies are still slightly warm.
Let the filling set completely before stacking or storing. They taste even better the next day, if they last that long. Enjoy!