Preheat your oven to 300°F (150°C). Lightly grease a 9x5 inch loaf pan to prevent sticking.
In a heatproof bowl, melt the chopped chocolate chips and 2 tablespoons of butter together over a pot of gently simmering water. Stir until smooth, then set aside.
In a separate medium bowl, whisk together the almond flour, protein powder, baking powder, and salt. Keep this mix handy.
In a large bowl, beat the softened 1/2 cup butter until it's smooth and creamy. Add the erythritol sweetener and continue beating for about 2 minutes until the mixture is lighter and well combined.
Beat in the eggs one at a time, making sure to scrape down the sides of the bowl. Stir in the orange zest and vanilla extract until everything is fully blended.
Gradually beat in half of your dry almond flour mixture. Then, pour in the orange juice and water, mixing until just combined. Finally, add the rest of the dry mixture and beat until the batter is smooth.
Pour half of the bread batter into your prepared loaf pan. Drizzle about two-thirds of the melted chocolate mixture over this batter. Use a knife to gently swirl the chocolate into the dough, creating pretty patterns.
Spoon the remaining bread batter on top, then add the rest of the chocolate glaze in a few dollops. Swirl it again lightly and smooth the top surface.
Bake for about 55 to 60 minutes, or until the top is a beautiful golden brown and a skewer inserted into the center comes out clean.
Let the bread cool in the pan for 5 minutes before carefully turning it out onto a wire rack to cool completely.
Once cool, drizzle any leftover chocolate glaze over the top for an extra touch of deliciousness!