Heat oven to 350°F. Grease a 10-inch ovenproof skillet and line with parchment paper.
In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt.
In a medium bowl, melt 2 tablespoons (28 grams) of butter in a microwave and let cool slightly, then whisk in eggs, followed by the buttermilk until combined.
Add wet ingredients to dry and stir until just moistened; do not overmix. Stir in the raisins or currants and caraway seeds.
Pour batter into prepared skillet. Brush top with remaining butter.
Bake until golden and firm to touch, about 1 hour.
Cool 10 minutes on a wire rack before slicing.
