Preheat oven to 400°F (200°C). Line or grease 12 standard muffin cups.
Whisk together the flour, sugar, baking powder, baking soda, and salt. Make a well in the center of the mixture.
In a separate bowl, stir together the butter, milk, eggs, and almond extract. Pour into the well in the flour mixture. Stir just until combined. Gently stir in the currants.
Divide the batter among the prepared muffins cups, filling each about 3/4 full. If desired, sprinkle the top of each with a pinch or two of almonds and sanding sugar.
Bake 14 to 18 minutes, or until the edges are browned and a pick inserted into the center comes out clean.
Cool the muffins in the pan on a wire rack for 5 to 10 minutes before serving.
Notes
These muffins can be stored in an airtight container at room temperature up to 3 days or in the freezer up to 3 months.