Making the Cookie Base:

1. Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. In a large bowl, cream together the softened unsalted butter and granulated sugar until light and fluffy.
3. Gradually add the all-purpose flour and mix until the dough forms.
4. Knead the dough a few times on a floured surface and roll it to 1/4 inch (6 mm) thickness.
5. Use a round cookie cutter to cut out shapes and place them on the prepared baking sheet.
6. Bake for 12-15 minutes, until the edges are golden. Let them cool on the baking sheet for a few minutes, then transfer to a wire rack to cool completely.

Making the Lemon Curd:

1. Whisk together fresh lemon juice, sugar, and egg yolks in a bowl.
2. Gently heat the mixture in a saucepan, stirring constantly until it thickens to a velvety, spoon-coating consistency.
3. If the curd seems too thin, add an extra egg yolk; if too thick, thin it out with lemon juice. Strain through a fine-mesh sieve if needed to remove lumps.

Assembling and Decorating:

1. Once the cookies and lemon curd are cooled, sandwich a dollop of lemon curd between two cookies.
2. For decoration, dust with powdered sugar or garnish with thin lemon slices, candied lemon peels, or a drizzle of fresh lemon icing.
3. Optionally, add edible flowers like lavender or nasturtiums for extra flair.