Heat oven to 350°F. Grease a 9 x 5-inch loaf pan and dust with flour, knocking out excess.

Grind almonds in a food processor fitted with the blade attachment until very fine, but not paste. Sift flour, baking powder, and salt into a bowl and set aside.

Cream shortening and 1 cup of the sugar in an electric mixer fitted with the paddle attachment until fluffy. Add eggs, one at a time, beating just long enough to incorporate. Add flour mixture and milk in 3 batches, beginning and ending with the flour. Beat each addition just until mixed, scraping down the sides of the bowl with a rubber spatula in between each batch. Add lemon extract, lemon zest, and almonds and stir just until mixed.

Scrape batter into prepared pan and bake until a toothpick inserted in the middle comes out clean, about 65 minutes. Transfer pan to a cooling rack and prepare glaze.

For the glaze: Combine remaining sugar and lemon juice in a small saucepan over medium heat, just until sugar is dissolved. (Do not boil). Pour the glaze over the warm cake and let sit until cake absorbs glaze completely.

Once cake has absorbed all the glaze, turn it out of the pan and allow to cool on rack. Once it's cool, wrap cake in plastic wrap and let stand at room temperature for 24 hours before serving.