• Preheat your oven to 325°F. Grease a loaf pan that is no more than 9-inches by 5-inches, and set it aside.
• In a small bowl, combine the flour, xanthan gum, cornstarch, salt and about 3/4 of the lemon zest, and whisk to combine well, working to break up any clumps of lemon zest. Set the bowl aside.

Make the pound cake batter.

• In the bowl of your stand mixer fitted with the paddle attachment (or in a large bowl with a hand mixer), place the butter and cream cheese and beat on medium-high speed until light and fluffy (about 5 minutes).
• Add the granulated sugar and mix to combine. Add the eggs and lemon juice, mixing well after each addition until the mixture is smooth.
• Add the flour mixture in 3 parts, beating well to combine after each addition. The batter will be smooth and thick, but relatively light.
• Scrape the batter into the prepared loaf pan, and smooth the top with a wet spatula.

Bake the pound cake.

• Place the loaf pan in the center of the preheated oven and bake until a tester inserted in the center of the pound cake comes out clean (about 50 minutes).
• If the loaf begins to brown too much, cover it tightly with a piece of aluminum foil.
• Remove the pound cake from the oven and allow it to cool in the pan for 15 minutes before transferring it to a wire rack to cool completely.

Make the glaze & assemble the cake.

• Once the pound cake is nearly cool, make the glaze. In a small bowl, place the confectioner’s sugar, salt, and the remaining lemon zest, and whisk to combine and to break up any lumps in the confectioner’s sugar or the lemon zest.
• Add the lemon juice, 1 teaspoon at a time, and mix well. Continue to add lemon juice by the teaspoon, stirring in between additions, until the glaze is thickly pourable.
• Pour the glaze over the cooled pound cake, and allow to set at room temperature.
• Slice and serve.