Measure out the vanilla skyr and place it in a strainer lined with a paper towel (or cheesecloth) over a bowl. Wrap the skyr with the towel/cheesecloth and add a weight on top to help push the water out of the skyr. Wrap the strainer and bowl with cling wrap and place it in the fridge overnight to strain.
Note: By removing the extra liquid (the whey) the skyr tart will be thicker and creamier once baked.
Preheat your oven to 325 degrees.
Grind the graham crackers in a mini food processor until they are uniform and fine. Set aside.
In a sauce pan place butter and melt until it is lightly golden brown.
Be careful not to let the butter go too dark. As soon as the butter is golden, cut the heat and pour the butter out of the saucepan.
Combine brown sugar, graham cracker crumbs, pinch of salt and the liquid brown butter until it resembles wet sand.
Press the graham cracker mixture evenly all over the pan, packing it down firmly so it is and evenly spread.
Note: If you are using a tart pan with a removable base: Spray the pan generously with baking spray or rub it with butter, this will help the tart slide out when removing the pan.
Note: If you are using a 6x6 square pan, create a double hang from 2 pieces of parchment. Use non-stick spray to adhere parchment to pan. This will help you pull out the tart when it is done.
Once the crust is has been spread evenly, place the graham cracker crust into the 325 degree oven for about 5 to 7 minutes until golden and puffy. Once baked, let it cool while you make the vanilla skyr filling.
Pull out the strained skyr from the fridge and discard any liquid/whey that has collected in the bowl underneath.
Combine the strained skyr along with the granulated sugar and whisk the mixture just until the sugar crystals are no longer gritty and are blended in.
Once beaten, add the egg yolk, vanilla extract, bourbon and salt and whisk just until combined and smooth. Pour the skyr mixture into the cooled graham cracker crust and smooth it out so it is even.
Find an empty baking pan or oven proof dish and fill it with water. Place this dish/pan of water in the bottom rack of your oven. This will help cook the tart evenly.
Place the skyr tart into oven and let it bake for about 15 - 18 minutes or just until there is a slight jiggle in the middle when tapped.
Once baked, turn the oven off and let the cheesecake cool in the oven for another 5 to 10 minutes with the oven door open. Then let the tart cool down to room temperature.
Once cooled to room temperature, wrap the tart loosely in a foil and refrigerate it for at least two hours, or until fully chilled. When ready to serve, decorate the tart with blueberries or fruit of your choice. Let the tart come to room temperature for serving. Enjoy!