Preheat oven to 350.
Line a 9x5x3 loaf pan with parchment paper (I always grease the inside first so the paper sticks).
In a medium bowl, whisk together almond flour, arrowroot, baking powder, and sea salt.
Next, grab your blender.
Add the bananas, coconut sugar, eggs, 1/3 cup peanut butter, and vanilla.
Blend until smooth.
Pour contents from blender into the bowl with the dry ingredients.
Pour half the batter into the loaf pan.
Dollop small spoonfuls of remaining 1/3 cup peanut butter and 1/4 cup jam over the batter.
Top with remaining batter, the dollop remaining 1/4 jam.
Use a toothpick or knife to swirl the jam.
Bake for 35 minutes.
Remove from oven and add aluminum foil to prevent too much browning.
Bake for an additional 17-20 minutes until a toothpick comes out clean.
Let cook for 15 minutes then lift loaf out of the tin and place on cooling rack for 20 minutes before slicing.