Start by preheating your oven to 350°F (175°C). In a large mixing bowl, combine the flour and sea salt. In another bowl, cream the chilled butter and sugar until light and fluffy. This usually takes about 3-4 minutes. It’s crucial not to skip this step, as it incorporates air into the butter, making the cookies lighter.

Now, add the pure almond essence and lemon zest into the butter mixture. Blend well. The aroma will make your kitchen smell heavenly. Slowly incorporate the flour mixture and mix until combined. Don’t overwork the dough; stop when you see the flour just blended in.

Once your dough is ready, it’s time to form the cookies. Scoop a tablespoon of dough and roll it into a ball. Place it on a baking sheet lined with parchment paper. Repeat this process until your dough is done. Leave enough space between each cookie, as they will slightly spread while baking.

Now, here comes the fun part! Use your thumb or the back of a teaspoon to create an indent in each dough ball. Make sure the well is deep enough to hold the jam, but not too deep that it falls apart. This step is crucial for holding that delicious raspberry preserve.

Carefully spoon a small amount of raspberry preserves into each thumbprint. Don’t worry if it spills over a bit; this just adds to the charm!

Place your cookie tray in the preheated oven and bake for about 15-20 minutes or until the edges are lightly golden. Keep an eye on them—every oven is a bit different. Once they’re done, let them cool on a wire rack.

If you want to add a little extra flair, mix the powdered sugar, milk, and almond essence in a bowl until smooth. Once the cookies are cool, drizzle the glaze over the top. Simple but elegant!