Preheat oven to 300F and grease a 9x5 inch loaf pan well.
In a heatproof bowl set over a pan of barely simmering water, combine the chocolate and butter. Stir until melted and smooth. Set aside
In a medium bowl, whisk together the almond flour, protein powder, baking powder, baking and salt. Set aside.
In a large bowl, beat the butter until smooth. Add the sweetenerand beat until lighter and well-combined, about 2 minutes.
Beat in the eggs, one at time, scraping down the beaters and sides of bowl with a rubber spatula as needed. Beat in the orange zest and vanilla extract.
Beat in half of the almond flour mixture, then beat in the orange juice and water. Beat in the remaining almond flour mixture until well combined.
Spread half of the batter into the prepared pan, and then dollop with about 2/3 of the chocolate glaze. Use a knife to swirl the chocolate into the batter.
Top with remaining batter, and swirl a bit more, then smooth the top.
Bake 55 to 60 minutes, or until top is deep golden brown and a tester inserted in the center comes out clean. Let cool in pan 5 minutes, then flip out onto a wire rack to cool completely.