Hot Cross buns - Guyana Dining

Name: Hot Cross buns - Guyana Dining
Cuisine: African
Ingredients: 1/2 cup dried currants; 1/2 cup raisins + 1 cup boiling hot water; 3/4 cup very warm milk divided into 1/2 cup and 1/4 cup (I used whole milk, Almond is fine); 1/2 cup white sugar + 1/2 tsp sugar; 1/4 cup (or 4 Tbsp) unsalted butter, softened; 1/2 tsp salt; 1 envelope active dry yeast about 3/4 Tbsp or 2 1/4 tsp; 2 large eggs well beaten; 3 1/2 cups unsifted all-purpose flour; 1/4 tsp ground cinnamon; 1/8 tsp a large pinch ground nutmeg; 1/4 teaspoon ground allspice; 1/2 teaspoon pure vanilla extract; Eggwash To brush the top of the buns; 1 large egg yolk; 2 tablespoons water; 1 teaspoon sugar; 1/2 cup powdered sugar mixed; 2 1/2 tsp milk