2tablespoonscold unsalted buttercut into small pieces
3/4cup(plus 1 to 2 tablespoons) buttermilk
1/2tablespoonunsulphered molassesnot blackstrap
2/3cupdried currants or raisinsoptional
Place a rack in the center of the oven and preheat the oven to 375 degrees F. Line a baking sheet with parchment paper. Set aside.
In the bowl of a food processor fitted with a steel blade, lightly pulse the all-purpose flour, whole wheat flour, sugar, baking powder, baking soda, and salt to combine. (If you prefer not to use a food processor, whisk the ingredients together in a mixing bowl.)
Scatter the butter pieces over the top. Pulse just until butter is incorporated but small pieces are still visible, about 10 to 15 pulses. (If you are not using a food processor, cut in the butter with a pastry blender or fork.)
In a separate, large mixing bowl, whisk together the egg, 3/4 cup plus 1 tablespoon buttermilk, and molasses.
Add the dry ingredient mixture and the currants to the bowl with the wet ingredients. By hand with a wooden spoon or spatula, stir until a soft dough forms. If the dough seems too dry, add 1 additional tablespoons buttermilk as needed.
Lightly flour a work surface, then dump the dough onto it. Knead the dough a few times (5 to 10-ish), then shape the dough into a round, slightly flattened loaf.
Transfer the dough to the prepared baking sheet. Using a serrated knife, lightly cut a 1/4-inch deep “X” on top of the loaf to allow air to escape.
Bake the Irish soda bread for 45 minutes, until a thin, sharp knife inserted into the center comes out clean. The dough will sound hollow when tapped on the bottom and the internal temperature should reach 200 degrees F.
Transfer the Irish soda bread to a wire rack. Let cool for at least 20 minutes. Slice and serve.
TO STORE: Store bread in an airtight storage container at room temperature for up to 4 days.
TO FREEZE: Freeze bread in an airtight freezer-safe storage container or ziptop bag for up to 3 months. Thaw at room temperature before serving.