Combine flours and baking powder. Beat butter, sugar, honey, lemon zest, and salt with a mixer on medium speed until pale and fluffy. Add eggs, one at a time, beating well after each addition. Mix in vanilla, almond, and one tablespoon of the lemon extracts. Working in batches, add flour mixture to butter mixture, scraping down sides of bowl after each addition. Fold in almonds with a rubber spatula. Wrap dough in plastic. Refrigerate until firm, about one hour.
Preheat oven to 325 degrees. Transfer dough to a floured surface. Divide dough in half, and roll each half into a 2-by-15-inch log. Transfer to a parchment-lined baking sheet.
Transfer baking sheet to oven. Bake until logs are slightly firm and pale golden, about 35 minutes. Remove logs from oven and reduce heat to 300 degrees. Let logs stand until cool enough to handle. Transfer to a cutting board. Cut logs on the bias into ½-inch-thick slices, returning to baking sheet, flat side down, as you work. Bake for 15 minutes, remove and flip, and continue baking for another 15 minutes. Let cool on sheet.
Create double boiler using a heat-proof bowl and sauce pan filled with two inches of water. Chop white baking chocolate and place in heat-proof bowl along with shortening and remaining tablespoon of lemon extract. Place bowl in sauce pan and simmer water. Stir chocolate mixture frequently until melted. Remove from heat.
Dip one side of biscotti in chocolate mixture until coated. Place chocolate side up on cookie sheet. Continue coating biscotti until all are coated and on cookie sheet. Place cookie sheet in refrigerator until chocolate coating is firm.
Recipe by Lesleigh Kowalski Frank at https://www.lesleighfrank.com/2015/04/28/white-chocolate-lemon-almond-biscotti/