Instructions

1. 1
   Adjust oven rack to middle position and heat oven to 350 °F.
2. 2
   Grease a 9x5-inch Pyrex loaf pan with 1 tablespoon softened butter; dust with 1 tablespoon cake flour, tapping out excess.
3. 3
   In a medium bowl, whisk together flour, baking powder, and salt; set aside.
4. 4
   In glass measuring cup or microwave-safe bowl, microwave butter, covered with plastic wrap, in 30-second bursts until melted. Whisk melted butter thoroughly.
5. 5
   In food processor, pulse sugar and lemon zest until combined. Add lemon juice, eggs, and vanilla; process until combined. With processor running, drizzle melted butter through feed tube. Transfer mixture to large bowl.
6. 6
   Sift flour mixture over batter in three steps, gently whisking after each addition.
7. 7
   Pour batter into prepared pan and bake 15 minutes.
8. 8
   Reduce oven temperature to 325 °F and continue to bake until deep golden brown and a skewer inserted in center comes out clean (about 35 minutes), rotating pan halfway through baking time.
9. 9
   Cool in pan for 10 minutes, then turn cake onto wire rack, poke on top and sides with a toothpick or skewer, and brush on lemon glaze (see below). Cool to room temperature (at least 1 hour).
10. 10
    While cake is cooling, bring sugar and lemon juice to boil in small nonreactive saucepan, stirring occasionally to dissolve sugar.
11. 11
    Reduce heat to low and simmer until thickened slightly, about 2 minutes.
12. 12
    Brush glaze onto cake.