Preheat the oven to 350 degrees. Grease and flour a bundt pan. Set aside.
In the bowl of a stand mixer, or in a large bowl using a hand mixer, beat the box cake mix, the pistachio pudding mix, the eggs, milk, oil, and almond extract on medium speed for 3-4 minutes until fully combined and smooth.
Pour 2/3 of the cake batter into a prepared bundt pan. Then add the chocolate syrup to the remaining 1/3 of the batter in the bowl. Stir to combine. Add the chocolate batter to the bundt pan. Take a knife and swirl the chocolate syrup batter with the yellow batter. Don’t totally mix them so you will get the marbled effect.
Bake in oven for 35 to 45 minutes, or until a toothpick entered into the center comes out clean. Mine takes exactly 40 minutes.
Cool in pan for about 15 minutes, then take out of the pan to finish cooling on a wire rack. Dust with powdered sugar and serve.
If you use a 9×13, start checking around the 30 minute mark.
You can add up to 1/2 cup of chocolate syrup if you would like it more chocolate(y).