Preheat oven to 375 degrees F. Coat a 10 X 15 baking pan with baking spray.

Line pan with parchment paper or wax paper.

Spray paper with more baking spray.

In a small bowl, mix together the flour, cocoa, baking powder, and salt.

In a large bowl, beat the eggs until thick and light colored.

Add sugar a little at a time, mixing until incorporated.

Add water and vanilla, mix until blended.

Add the dry ingredients that have been previously combined.

Beat until batter is smooth.

Pour into cake pan and smooth out the batter.

Bake for 12 to 15 minutes, or until a toothpick inserted in the center of the cake comes out clean or with a few crumbs.

Loosen the edges of cake from the pan.

Place a towel over cake.

Cover with a cooling rack.

Invert the cake.

Slowly and gently remove the paper from the bottom of the cake.

Sprinkle the bottom of the cake with powdered sugar.

Cut off edges of cake if crusty.

Roll the cake, starting with the short end, keeping the towel between the rolls.

All the cake to cool for several hours on the cooling rack.

Once completely cool, gently unroll the cake and remove the towel.

Remove the box of ice cream from the freezer.

Open the box at all openings so there is a block of ice cream.

Slice ice cream in 1/4 to 1/2 inch slices and place on the unrolled cake.

Re-roll the cake and wrap tightly in plastic wrap.

Place in freezer and allow ice cream to refreeze. Depending on the thickness of the ice cream and freezer temperature this could take 4 hours or overnight.