Preheat convection oven to 350 degrees F and line 10x15-inch baking sheet with parchment paper.

In large bowl, combine flaxseed meal and 5 Tbsp. water. Set aside 2 minutes to thicken.

Add wet ingredients to thickened flaxseed and mix well.

Add sifted dry ingredients to wet ingredients and mix well. Add white vinegar and gently mix.

Pour batter into prepared baking sheet and smooth down evenly. Gently drop the pan on a flat surface 2-3 times to help the batter spread evenly.

Bake 12 minutes or until a toothpick comes out clean. Cool completely.

Line an 8-inch square baking tin with parchment paper or plastic wrap.

Cut sponge in half. With paper still attached, cut and trim edges of each half so they fit into the bottom of the baking tin.

Peel off baking paper from one sponge half, being careful not to let it fall apart, and lay it on the bottom of the tin. (Note: If sponge cracks, do not worry as the ice cream will glue it together.)

Scoop out chilled and solidified coconut cream from canned coconut milk and add to a blender (about 6.3 oz). Add ice cream ingredients and blend well. Optional: Add lemon juice and condensed milk.

Pour it over prepared sponge and smooth down evenly.

Carefully peel off paper from other sponge half, place it on top of ice cream and press down lightly. Freeze overnight.

Remove from tin and let stand at room temperature until slightly softened. Cut with a warm knife.