Preheat the oven to 375 degrees. Line a sheet pan with parchment paper.
Combine the flour, sugar, baking soda, and salt in the bowl of an electric mixer.
Add the butter and mix on low speed until the butter is mixed into the flour.
Mix the buttermilk and egg together.
With the mixer on low speed, slowly add the buttermilk mixture to the flour mixture.
Combine the currants with 1 tablespoon of flour and mix into the dough.
It will be a very wet dough.
Dump the dough onto a well-floured surface and knead it a few times.
Shape into a round loaf.
Place the loaf on the prepared sheet pan and cut an X into the top of the loaf with a serrated knife.
Bake for 45 to 55 minutes, or until a toothpick comes out clean.
When tapped the loaf will have a hollow sound.
Cool on a baking rack. Serve warm or at room temperature.