Preheat the oven to 350°F/180°C and generously grease your bundt pan with cooking spray or butter.
Cook the blueberries in a small saucepan over medium heat. Heat until the berries start to release their juices.
1 ½ cup blueberries
Smash the berries with a fork while they cook until a thin, jammy consistency is reached. Turn off the burner and set the saucepan aside.
In a medium bowl, whisk together the flour, cocoa powder, baking soda, and salt. Set aside.
2 cups all purpose flour, ⅓ cup dutch-processed cocoa powder, 1 teaspoon baking soda, 1 teaspoon salt
In a large mixing bowl, whisk together avocado oil, vanilla extract, and coconut sugar. Mix well and then whisk in the steaming hot water. Add eggs one at a time, whisking well between additions to make sure they are fully incorporated.
¾ cup avocado oil, 1 tablespoon vanilla extract, 1 ½ cup coconut sugar, ½ cup hot water, 2 large eggs
Mix the dry ingredients into the wet ingredients with a rubber spatula until just combined. Then, mix in the Greek yogurt and scrape the sides of the bowl to make sure that no dry patches of flour remain.
½ cup Greek yogurt
Pour ⅔ of the batter into the prepared bundt cake pan. Then, scoop the blueberry filling on top, trying not to let it touch the sides of the pan. Add the rest of the batter on top and smooth.
Bake the cake for 35-40 minutes until a toothpick or skewer inserted into the center comes out with just a few moist crumbs.
Remove the cake from the oven and allow it to cool for 15-25 minutes. Then, turn the pan over onto a wire cooling rack. After 5 more minutes, lift the pan to let the cake slide out. Let it cool completely before icing.