This is my easy explanation.
Use your favorite brownie mix (my personal favorite box mix is Ghirardelli Dark Chocolate). Or, use your favorite recipe. Prepare per the instructions and then pour approximately 1/2 C Jessi’s Flaming Fruit Sauce Blueberry-Ginger in a zig-zag pattern over the top. Use a butter knife to zig-zag the sauce in the other direction, swirling it down into the batter. Bake as instructed, and insure an inserted toothpick comes out clean.
If you want Blueberry-Ginger flavor in every bite, I don't add water at all to the recipe. Whatever the amount of water required, use Blueberry-Ginger instead. Mix it right into the batter instead of swirling it through in the pan.