Spatula and buterknife - use the axe to split wood to the required thickness and the knife to carve the wood into shape (google for images)
Sledge - use the axe to split the wood into planks and struts and to curve the bottom corners of 2 planks, use the knife to cut joints in the planks and struts to form a sledge shaped structure (google sledge for images) you may want some cordage and glue to secure the joints.