Preheat oven to 200C | 390F. Spray a baking tray with cooking oil spray; set asideWhisk together the buttermilk, sugar, vanilla, egg and greek yogurt. Set aside.In a separate bowl, mix the flour/s, baking powder and salt together. Cut in the cold butter with a flat-bladed knife (or pastry blender), or with your fingertips, rub butter into flour mixture until it resembles fine breadcrumbs or coarse meal. Gently fold in the berries and half of the chocolate chunks to evenly coat in the flour mix. Add the milk mixture, and stir through until just combined.Turn onto a lightly floured surface and knead gently until smooth. Pat dough into a 9-inch circle onto your baking tray and sprinkle with remaining chocolate chunks. With a floured knife (dip knife into flour and shake of excess), cut dough into 8 wedges all the way through; then cut those wedges in half to make 16 slices.Brush with the (extra) butter and sprinkle over the sugar.Bake for 18-20 minuets, or until set (when a toothpick comes out clean).Drizzle with the cream cheese glaze