Cream margarine and sugar. Beat in honey and vanilla. Sift dry ingredients into separate bowl. For graham crackers, sift dry ingredients into creamed ingredients alternately with 1/4 cup water. For cereal bits, sift dry ingredients into creamed ingredients alternately with 1/2 cup water. Mix thoroughly once everything has been added.
For Graham Crackers, dough should be soft and will be sticky, but forms a ball. For cereal bits, dough should be very soft and not form a ball.
For Crackers: Refrigerate dough for at least one hour. Using sweet rice flour, roll portions of dough on plastic wrap or parchment paper to about 1/4″. Cut into squares and prick with fork. Transfer to baking sheet. Bake in preheated 325 °F oven for 15-20 minutes. Crackers should just be getting browned. Cool slightly on sheet before removing to rack to cool completely. Store in airtight containers.
For Cereal Bits: Transfer dough to piping bag fitted with small flat (#48 works well) or star tip (#75 works well). Pipe 1″ squiggles onto parchment lined baking sheets. Sprinkle with mixture of 2 Tbsp caster sugar plus 1/2 tsp pumpkin pie spice. Bake at 325 °F for 15 minutes or until starting to brown. Cool slightly on sheets before removing to linen dish towel to cool completely. Store in airtight containers.