Weigh or measure into a bowl the flour, baking powder, salt, ginger, running a whisk through to blend and set aside. In another small bowl, weigh or measure the powdered sugar and set that bowl aside also—next, zest and juice two lemons. Make sure the zest and juice are in separate containers.
In a stand or handheld mixer, beat the butter till it is creamy, light, and fluffy, about 3 minutes. Turn the mixer down to low and slowly add the powdered sugar. Turn the mixer to medium and mix for about 2 minutes. Scape down the sides and finish blending the sugar into the butter. Add the lemon juice and the zest and incorporate it. Turn the mixer down and slowly add the flour mixture. Stop the mixer and scrape the sides, and across the bottom, then add the hazelnuts. Turn the mixer on for about 1 minute to get the hazelnuts to go evenly throughout the dough.
You want to take the dough out of the bowl and onto a hard surface or pastry mat that has been lightly dusted with flour and check to see that everything is mixed. I divide the dough into two even sections. You want to make a log shape out of each half. My logs were about 9-½ inches long. You want to wrap each log section with plastic wrap and set on a sheet pan before sticking them into the refrigerator for 45 minutes to harden.
Preheat your oven to 350°, and line 2 cookie sheet pans with parchment paper and set them aside. Taking one log out of the refrigerator, unwrap the plastic wrap, and slice out about 14 to 16 cookies. You can fit them all onto one pan; they do not spread much when baking—Bake for 12 to 14 minutes. Repeat with the second log. You should get about 2-½ dozen cookies.