Preheat oven to 350°F (175°C). Grease and flour a 9 x 13 inch baking pan.

In a bowl, whisk together flour, cinnamon, ground ginger, ground allspice, baking powder, baking soda, and salt.

In a separate large bowl, combine melted butter, apple butter, and brown sugar. Mix well until smooth.

Add canola oil (or vegetable oil) to the apple butter mixture and stir.

Stir in raisins.

In a separate bowl, whisk together buttermilk and beaten egg.

Add vanilla extract to the buttermilk mixture.

Add the wet ingredients to the apple butter mixture and mix until well combined.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.

Pour the batter into the prepared baking pan and spread evenly.

Bake for 25-35 minutes, or until a toothpick inserted into the center comes out clean.

Let the cake cool in the pan for 25 minutes on a wire rack, or until just warm.

Prepare the glaze: In a bowl, whisk together icing sugar, melted butter, and vanilla extract.

Add hot water, one tablespoon at a time, until the glaze reaches desired consistency.

Drizzle the glaze over the warm cake. Alternatively, spread the glaze thinly and let the cake cool completely.