Line a 12x17" jelly roll pan with parchment paper.
In bowl whisk together the butter, milk, apple butter and sugars until combined.
Add in the eggs and vanilla. Blend until smooth.
Whisk in the flour, baking soda and apple pie spice until blended.
Pour and spread the batter into pan and bake for about 20 minutes or until the center of the cake springs back when you touch it.
Remove from oven and let cool on a wire rack.
In a bowl, whisk together the frosting ingredients until you reach the desired consistency of a glaze.
Pour and spread the glaze over the cooled cake and sprinkle with pecans if desired.
Let sit for about 15 minutes to let frosting set.
Then slice and serve. Store in an airtight container at room temperature.
The calories shown are based on the cake being cut into 16 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**