Preheat the oven to 350°F. Grease an 8-inch round springform cake pan and line with parchment paper.
Cream together the butter and sugar in a large bowl until fluffy. Slowly add the eggs, one at a time, and stir well. Sift in the flour, baking powder, and xanthan gum, then add the lemon juice and lemon zest and fold into the mixture.
Transfer the batter to the prepared pan, smooth out the top, and bake in the preheated oven for 35–40 minutes.
Remove the cake from the oven and let cool in the pan for 45 minutes before transferring it to a wire rack.
To make the icing, mix together the confectioners’ sugar, lemon juice, and lemon zest in a large bowl. Drizzle the lemon icing over the cake and decorate with the raspberries to serve.
Excerpted with permission from <a href="http://www.amazon.com/gp/product/1445498278/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1445498278&linkCode=as2&tag=craftfocom-20">"Gluten Free Baking (Love Food)"</a> by Michael McCamley and published by Parragon Books.