Preheat the oven to 350˚. Make the crust: In a food processor, pulse the cashews until they become a fine crumb, about 10 times. Add the almond flour, ginger and a pinch of salt and pulse a couple times to combine. Pour this mixture into a medium bowl, add the melted butter and honey and stir with a fork to combine until it resembles coarse meal. Press the mixture evenly onto the bottom of a 9-by-13-inch baking pan. Bake until light golden brown, about 15 minutes. Set aside.
Reduce the oven temperature to 300˚. Make the filling: In a stand mixer fitted with the paddle, beat the cream cheese on medium-high speed until smooth, 2 minutes. Mix in the sour cream, honey, lemon zest and salt on medium speed, scraping the side of the bowl, until smooth, 2 minutes. With the mixer on low speed, add the eggs one at a time. Add the vanilla and mix to combine.
Pour the batter onto the crust. Bake until it begins to brown around the edges and the center is set, about 1 hour. Let cool slightly. While warm, slice into 24 squares, then cover with plastic wrap and chill until cold. Garnish with lemon zest, if desired, and serve chilled. Store for up to 3 days covered in the fridge.