01 -
Turn your oven to 350°F (175°C) and either grease a loaf pan (8-1/2 x 4-1/2 inches) with spray or line it with parchment.
02 -
Use a whisk to evenly mix flour, salt, and baking powder in a small bowl. This helps in removing any clumps.
03 -
In a large bowl, rub together the sugar and lemon zest to release the citrus oils. Add in sour cream, eggs, vanilla, and lemon oil, then whisk everything until smooth.
04 -
Take half of the dry mix and fold it gently into the wet mix. Once combined, do the same with the remaining dry ingredients.
05 -
Pour in the vegetable oil little by little while stirring the batter constantly with a silicone spatula. Keep going until it's fully mixed in.
06 -
Scoop out half a cup of batter into a small bowl and stir in the blackberry jam and food coloring (if you're using it).
07 -
Fold the flour-coated blackberries gently into the rest of the batter in your main bowl.
08 -
Pour most of the plain blackberry batter (around two-thirds) into your prepared pan. Layer the jammy batter on top, then finish with the rest of the plain batter.
09 -
Let the loaf bake for about an hour (55-65 minutes) or until you can poke it with a toothpick and it comes out mostly clean.
10 -
Let the bread sit in the pan for about 5-10 minutes after baking. Run a knife around the edges, take it out, and let it cool completely on a rack.
11 -
Whisk powdered sugar with salt and 2 tablespoons of lemon juice in a bowl. If you want it thinner, add more juice drop by drop.
12 -
Pour or drizzle the glaze over your fully cooled bread. Let it rest for 10 minutes so it can set nicely.