For your cookies, in a bowl, cream together ½ cup of sugar and your room-temperature butter with a mixer. Beat for 2 minutes on a medium speed until light and fluffy

In a separate bowl, whisk together your flour, cornstarch, salt, and lavender

Pour your dry ingredients into your butter mixture and stir together with a spatula until just combined. Your dough will be crumbly, have no fear! Once combined but crumbly, use your hands to press your dough together. Cover your bowl and pop it in the fridge for 20 minutes to let the flavors meld and allow the flour to absorb into the dough

Preheat your oven to 350°F and line a baking sheet with parchment paper

Once set, roll 2 tablespoons of dough at a time into a ball, compressing as needed to form. Roll each ball in a bowl with your remaining 1 tablespoon of sugar, and place on a cookie sheet about an inch apart

Once your dough is rolled, use your thumb to press an indent into the center of each cookie; be careful not to push all the way through. Because this is a dry dough, it will likely crack a bit as you make your indent. Just use your fingers to press the edges back together

Bake for 15 minutes. At the halfway mark, remove your cookies from the oven and use a teaspoon to re-form the indent as it will have likely puffed up a bit as the cookies baked. Rotate your tray and place the cookies back in the oven for the remainder of their baking time. They will still be pale, but the bottoms will be lightly golden. You want your shortbread to have a lovely chew in the middle, so don’t overbake these!

Cool on a wire rack completely

While your cookies cool, place your raspberries in a small pot over medium-low heat. Stir and start to mash them up with a spoon, cooking them down by half. When it’s ready, you should be able to run your spoon through the middle of your mixture to form a line, without the mixture running back together. Turn off the heat and pour your raspberries through a fine mesh strainer into a bowl. Use a spoon to press out any extra raspberry juice - you just want to catch the seeds here. Throw away the seeds and set the mixture aside to cool

Once your cookies are cool, place your chopped white chocolate in an even layer in a heat-proof bowl. In a small pot, add your heavy cream and place it on the stove over medium heat. Once the liquid begins to steam and has a few bubbles around the edge, immediately pour over your chopped white chocolate. Cover the bowl with a lid or plate and let sit for 5 minutes before removing the lid and whisking until smooth. Fold in your raspberry puree as much or as little as you want to. I like a swirled look, so I just briefly fold it through

Spoon a little bit of ganache into each thumbprint and top with any extra lavender and/or pieces of fresh raspberries

Allow the ganache to set in your thumbprints for at least an hour before enjoying!