Preheat your oven to 350°F (175°C). Grease and flour a cake pan.
In a bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt.
In a separate large bowl, cream together the softened butter and granulated sugar until light and fluffy. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.
Gradually add the dry ingredients to the wet ingredients in three parts, alternating with buttermilk. Begin and end with the dry ingredients. Mix until just combined. Gently fold in the brunoise mix into the batter until evenly distributed.
Pour the batter into the prepared cake pan and smooth the top. Bake in the preheated oven for 35-40 minutes or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely.
