Make these muffins today and they will serve as a great dessert after the evening meal plus any leftovers are perfect for those lunchboxes.
Preheat the oven to 375F.
Line a 12 hole muffin tin with paper liners.
Use a small pan over low heat to melt the butter and chocolate pieces. Stir as needed until melted and smooth. Remove from heat and let cool slightly.
Using a mixing bowl, use an electric mixer on medium to combine the sugar, egg, buttermilk and vanilla.
Measure the flour and baking soda and stir the soda into the flour.
Add the dry ingredients to the mixture, folding in gently. Don't overmix.
Add the berries and gently fold in.
Divide the batter into the lined muffin tin, filling each to the top.
Place into the preheated oven and bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.
Remove and place onto a cooling rack. Let sit for a few minutes until you can handle them, then place each muffin directly onto the cooling rack.