Preheat oven to 350°F (180°C). Line a large baking sheet with parchment paper.
In the bowl of a stand mixer fitted with the paddle attachment, beat sugars, eggs, extracts, and lemon zest at medium-high speed until thick and pale in color and mixture falls off paddle in a ribbon, 4 to 5 minutes.
In a medium bowl, whisk together flour, baking powder, and salt. Add flour mixture to sugar mixture, and beat at low speed until combined, stopping to scrape bottom and sides of bowl and paddle. Add almonds and sprinkles; beat just until combined.
Using wet hands, divide dough in half (about 283 grams each); on prepared pan, shape each half into a log about 8 inches long and ¾-inch-thick.
Bake until logs feel firm to the touch, 25 to 30 minutes. Let cool on pan on a wire rack until cool enough to handle, 20 to 30 minutes. Reduce oven temperature to 300°F (150°C).
Gently transfer logs to a cutting board; using a serrated knife, cut logs crosswise into ¾-inch-thick slices. Place slices, cut side up, on same pan.
Bake until slices are firm to the touch, 15 to 20 minutes. Remove from pan, and let cool completely on a wire rack.
Dip end of cooled biscotti into melted white chocolate, letting excess drip off. Place on a piece of parchment paper, and top with sprinkles. Let stand until chocolate is set, 15 to 20 minutes. Store in an airtight container for up to 5 days.