Rhubarb Curd Shortbread

Wash the rhubarb and trim as little off the ends as possible. Cut rhubarb into 1-inch chunks. In a small saucepan, heat rhubarb, 1/4 cup sugar, and water on medium. Cook until rhubarb falls apart and there are no whole pieces left, adding water by the tablespoon if rhubarb sticks to the bottom of the pan. Stir in the raspberry powder and use an immersion blender to puree the mixture

Preheat oven to 350 degrees. Now make the shortbread: blend all ingredients in a stand mixer or food processor until combined. Wrap in plastic and refrigerate about 1 hour. Then, dump dough into pan and use fingertips to press evenly into pan. Bake 30 minutes, until golden. Let cool on a rack or on the counter.

Add a couple of inches of water to the pot of a double boiler and set over medium heat. Put egg yolks, butter, remaining sugar, lemon zest, and lemon juice in the bottom of a double boiler and whisk to combine. When sugar has dissolved completely, add the rhubarb puree by the spoonful, to temper the eggs. when all rhubarb has been added. set bowl over pot; the water should be simmering. Continue stirring the rhubarb mixture; after about 5 minutes, the mixture will be wam and slightly thickened. At this point, remove from the heat. Press through a strainer--this will give your curd that smooth pudding-like texture.

Use an offset spatula to spread curd evenly over shortbread. It should make a layer equal in thickness to the shortbread. Bake another 10 minutes, then remove from oven and cool on rack. Refrigerate about 20 minutes and you'll find they have firmed up enough to cut cleanly. Cut into bars--either 16 2" squares or 32 pieces 1" x 2"