Preheat oven to 425 degrees.

In a large bowl, whisk together the baking powder, salt, 1 1/2 cups flour and sugar. Add the butter and mix with a pastry blender or fork until pea-size pieces form. Add the milk, irish cream and mix with a fork until a shaggy dough forms. Transfer the dough to a lightly floured surface and gently knead until dough begins to form a ball, approximately 3 - 4 times.

Gently pat dough into a 1-inch-thick circle. Using a 2 1/2-inch round biscuit cutter, cut out scones. Combine the scraps and repeat, patting out and cutting to make 8 scones. Transfer baking sheet lined with parchment and brush with the egg. Sprinkle the tops with the turbinado sugar.

Bake the scones until golden brown, 12-15 minutes. Transfer to a wire rack and allow to cool to room temperature.

In a small bowl, whisk together the Irish cream and sugar until smooth. Drizzle the mixture over the scones.

Serve at room temperature with jam, if desired.