In a small bowl, soak raisins in the mixture of 1/2 cup warm water and 1 tablespoon rum until raisins become soft (about 10 minutes). Drain.

Place butter, granulated sugar, brown sugar, salt and nutmeg in a mixing bowl. Mix on low speed until light and fluffy, about 2-3 minutes.

Add egg and vanilla extract and blend in.

Add flour, baking powder and rolled oats. Mix until just combined (do not overmix, or gluten will develop).

Blend drained raisins in last.

Take 2 tablespoons of dough at a time, spoon on baking sheet lined with baking paper, or form into a ball. Place cookies 2" apart.

OPTIONAL STEP: Place cookies in refrigerator for at least 30 minutes to prevent them from spreading too much.

Bake in preheated 350 F (175 C) oven for 13-15 minutes or until the edges of cookies are brown and the top of cookies are light in color.