Prep the pan: Grease and line a 9x5-inch loaf pan with parchment for easy removal.
Heat the oven: 350°F (175°C).
Room temp ingredients: Eggs and yogurt should be at room temp for a smoother batter.
In a medium bowl, whisk flour, baking powder, and salt. Set aside.
In a large bowl, whisk sugar and eggs until thick and slightly pale, 1 minute.
Whisk in oil, yogurt, limoncello, lemon juice, lemon zest, and vanilla until smooth.
Sprinkle the dry ingredients over the wet and fold gently with a spatula until just combined. Do not overmix.
Pour the batter into the lined pan and smooth the top.
Bake 45–55 minutes, until a toothpick comes out with a few moist crumbs. If the top browns quickly, tent loosely with foil for the last 10 minutes.
Cool the cake in the pan for 10 minutes.
While the cake cools, combine limoncello, lemon juice, and sugar in a small saucepan.
Warm over low heat, stirring, until the sugar dissolves. Remove from heat.
Poke holes all over the warm cake with a skewer.
Brush the syrup slowly over the cake, letting it soak in. Use every drop.
Let the cake cool completely on a rack.
Whisk powdered sugar with lemon juice (and limoncello if using) to make a thick, pourable glaze.
Drizzle over the cooled cake. Let set 20 minutes before slicing.
