Once well combined, stir in the blueberries.
Grease a loaf pan and add half of the batter. Snip the edge of the blueberry sauce packet, and spread it evenly (or as evenly as you can) over the batter. Add the rest of the batter on top of the blueberry sauce, and pop in the oven for 48-52 minutes.
While the cake is baking, you can make the glaze! Now, I didn't use exact measurements for the glaze, I just kind of improvised, and it turned out great. But don't worry! It's so very easy. Just take it slow. Add the juice of one lemon to a small bowl. Slowly add confectioner's sugar (powdered sugar), a few tablespoons at a time, and whisk it into the lemon juice. I would add a tablespoon or so, whisk til it was combined, then add another one, whisk until combined, and so on. Taste as you go; you want to make sure you still have a tangy lemon flavor, in addition to the obvious sweetness. Once your glaze is about the consistency of sweetened condensed milk, and it will stream off your whisk, but will coat the side of your bowl, you're in good shape.
Once your cake is done, take it out of the oven and admire your handiwork!! I let it cool for a while in the pan so it stays together well, and then I took it out of the pan and put it on a serving plate.
Once it's cool, drizzle your glaze over the top, slice and serve! It's a very simple little cake, easy enough for a weeknight dessert, or evn good for breakfast or brunch! It would be yummy as muffins too, or even with some lemon buttercream as cupcakes!
No matter how you eat it, it's an easy dessert and perfect for spring. I hope you'll try it!