Line the bottom and sides of a 13×9 metal baking pan with parchment paper or foil.
In a medium bowl, mix together butter, sugar, salt, and egg yolks with a spoon until smooth. Add in the flour and mix until just combined.
1 1/4 cup unsalted butter, 1 cup granulated sugar, ¾ tsp. table salt, 2 large egg yolks, 3 cups plus 3 tbs. flour
Remove 2 cups of the crust mixture and press into the lined pan. Set the unused portion of the crust aside.
Place the pan in the freezer while the oven preheats to 325 degrees F.
While the oven is preheating and the crust is chilling start on the black currant topping. Combine blackcurrants,sugar and water in a saucepan and bring to a boil. Then, reduce heat to medium-low and continue simmering for 8 minutes.
2½ cups fresh or frozen black currants, 1 cup granulated sugar, ¼ cup water
Remove from the heat and let the mixture cool while the crust bakes.
Once the oven is preheated, remove the crust from the freezer and place in the oven to bake for 20 minutes, or until the sides are lightly browned. Then remove from the oven, and increase oven temperature to 350 degrees
Spread the black currant mix (or Plaid Shirt Farms Black Currant Jam) on top, and sprinkle the left over crust mixture on top. Place the bars near the top of the oven and bake for 25 minutes, or until the streusel is lightly browned.
1 jar Plaid Shirt Farms Black Currant Jam