For the honey mustard mayo: In a bowl, whisk the ingredients until smooth. Refrigerate.
For the sliders: Core and thinly slice the apples, then drizzle with lemon juice.
To assemble: Slice the buns if needed. Spread mayo on both sides, layer with turkey, apples, and baby spinach. Add Bergeron Inspiration Cracker Cut Slices and close.
To serve cold: Arrange the sliders on a platter and serve immediately, or pack for a picnic or lunch box.
To serve warm: Preheat the oven to 175 °C (350 °F). Place the sliders in a dish, cover with foil and bake 10 minutes, until the cheese is melted and the buns are hot. Remove the foil for the last 2 minutes to brown.
Let rest a few minutes before serving.