12 tablespoon unsalted butter, at room temperature
1 cup sugar
2 tablespoon extra-virgin olive oil
1 large egg
1 egg yolk
3 tablespoon limoncello
1/2 teaspoon vanilla extract
1 lemon, zested and juiced
8 ounce white chocolate, chopped
1/2 cup pistachios, finely chopped
Whisk the all-purpose flour, semolina flour, baking powder, baking soda and salt in a large bowl. In a separate bowl, beat the butter and sugar with a mixer on medium speed until light and fluffy, about 2 minutes.
Whisk the olive oil, whole egg, egg yolk, limoncello, vanilla, lemon zest and lemon juice in a large liquid measuring cup or bowl. Add to the butter mixture and beat on medium speed until smooth. Reduce the mixer speed to low; add the flour mixture and beat until just combined. Cover the dough with plastic wrap and chill 30 minutes.
Preheat the oven to 350 degrees F. Line 2 baking sheets with parchment paper. Roll the dough into 2-inch-long, 1/2-inch-thick logs; arrange about 2 inches apart on the prepared baking sheets. Bake in batches until golden around the edges, about 18 minutes, rotating the baking sheets halfway through. Let cool 2 minutes on the baking sheets, then transfer to racks to cool completely.
Meanwhile, put the white chocolate in a heatproof bowl and set over a saucepan of barely simmering water (do not let the bowl touch the water); stir until the chocolate melts. Drizzle the cookies with the melted white chocolate and sprinkle with the pistachios. Let set at room temperature, about 15 minutes.